upstream commit

update sftp client and server to new buffer API. pretty
 much just mechanical changes; with & ok markus

9 files changed, 972 insertions, 668 deletions

diff --git a/progressmeter.c b/progressmeter.c
index bbbc7066..319b7470 100644
--- a/progressmeter.c
+++ b/progressmeter.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: progressmeter.c,v 1.40 2013/09/19 00:24:52 djm Exp $ */
+/* $OpenBSD: progressmeter.c,v 1.41 2015/01/14 13:54:13 djm Exp $ */
 /*
  * Copyright (c) 2003 Nils Nordman.  All rights reserved.
  *
@@ -65,7 +65,7 @@ static void update_progress_meter(int);
 
 static time_t start;		/* start progress */
 static time_t last_update;	/* last progress update */
-static char *file;		/* name of the file being transferred */
+static const char *file;	/* name of the file being transferred */
 static off_t start_pos;		/* initial position of transfer */
 static off_t end_pos;		/* ending position of transfer */
 static off_t cur_pos;		/* transfer position as of last refresh */
@@ -248,7 +248,7 @@ update_progress_meter(int ignore)
 }
 
 void
-start_progress_meter(char *f, off_t filesize, off_t *ctr)
+start_progress_meter(const char *f, off_t filesize, off_t *ctr)
 {
 	start = last_update = monotime();
 	file = f;
diff --git a/progressmeter.h b/progressmeter.h
index 10bab99b..bf179dca 100644
--- a/progressmeter.h
+++ b/progressmeter.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: progressmeter.h,v 1.2 2006/03/25 22:22:43 djm Exp $ */
+/* $OpenBSD: progressmeter.h,v 1.3 2015/01/14 13:54:13 djm Exp $ */
 /*
  * Copyright (c) 2002 Nils Nordman.  All rights reserved.
  *
@@ -23,5 +23,5 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-void	start_progress_meter(char *, off_t, off_t *);
+void	start_progress_meter(const char *, off_t, off_t *);
 void	stop_progress_meter(void);
diff --git a/sftp-client.c b/sftp-client.c
index 990b58d1..574da833 100644
--- a/sftp-client.c
+++ b/sftp-client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp-client.c,v 1.115 2014/04/21 14:36:16 logan Exp $ */
+/* $OpenBSD: sftp-client.c,v 1.116 2015/01/14 13:54:13 djm Exp $ */
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
  *
@@ -47,7 +47,8 @@
 #include <unistd.h>
 
 #include "xmalloc.h"
-#include "buffer.h"
+#include "ssherr.h"
+#include "sshbuf.h"
 #include "log.h"
 #include "atomicio.h"
 #include "progressmeter.h"
@@ -83,8 +84,8 @@ struct sftp_conn {
 	struct bwlimit bwlimit_in, bwlimit_out;
 };
 
-static char *
-get_handle(struct sftp_conn *conn, u_int expected_id, u_int *len,
+static u_char *
+get_handle(struct sftp_conn *conn, u_int expected_id, size_t *len,
     const char *errfmt, ...) __attribute__((format(printf, 4, 5)));
 
 /* ARGSUSED */
@@ -98,36 +99,39 @@ sftpio(void *_bwlimit, size_t amount)
 }
 
 static void
-send_msg(struct sftp_conn *conn, Buffer *m)
+send_msg(struct sftp_conn *conn, struct sshbuf *m)
 {
 	u_char mlen[4];
 	struct iovec iov[2];
 
-	if (buffer_len(m) > SFTP_MAX_MSG_LENGTH)
-		fatal("Outbound message too long %u", buffer_len(m));
+	if (sshbuf_len(m) > SFTP_MAX_MSG_LENGTH)
+		fatal("Outbound message too long %zu", sshbuf_len(m));
 
 	/* Send length first */
-	put_u32(mlen, buffer_len(m));
+	put_u32(mlen, sshbuf_len(m));
 	iov[0].iov_base = mlen;
 	iov[0].iov_len = sizeof(mlen);
-	iov[1].iov_base = buffer_ptr(m);
-	iov[1].iov_len = buffer_len(m);
+	iov[1].iov_base = (u_char *)sshbuf_ptr(m);
+	iov[1].iov_len = sshbuf_len(m);
 
 	if (atomiciov6(writev, conn->fd_out, iov, 2,
 	    conn->limit_kbps > 0 ? sftpio : NULL, &conn->bwlimit_out) !=
-	    buffer_len(m) + sizeof(mlen))
+	    sshbuf_len(m) + sizeof(mlen))
 		fatal("Couldn't send packet: %s", strerror(errno));
 
-	buffer_clear(m);
+	sshbuf_reset(m);
 }
 
 static void
-get_msg(struct sftp_conn *conn, Buffer *m)
+get_msg(struct sftp_conn *conn, struct sshbuf *m)
 {
 	u_int msg_len;
+	u_char *p;
+	int r;
 
-	buffer_append_space(m, 4);
-	if (atomicio6(read, conn->fd_in, buffer_ptr(m), 4,
+	if ((r = sshbuf_reserve(m, 4, &p)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	if (atomicio6(read, conn->fd_in, p, 4,
 	    conn->limit_kbps > 0 ? sftpio : NULL, &conn->bwlimit_in) != 4) {
 		if (errno == EPIPE)
 			fatal("Connection closed");
@@ -135,12 +139,14 @@ get_msg(struct sftp_conn *conn, Buffer *m)
 			fatal("Couldn't read packet: %s", strerror(errno));
 	}
 
-	msg_len = buffer_get_int(m);
+	if ((r = sshbuf_get_u32(m, &msg_len)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	if (msg_len > SFTP_MAX_MSG_LENGTH)
 		fatal("Received message too long %u", msg_len);
 
-	buffer_append_space(m, msg_len);
-	if (atomicio6(read, conn->fd_in, buffer_ptr(m), msg_len,
+	if ((r = sshbuf_reserve(m, msg_len, &p)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	if (atomicio6(read, conn->fd_in, p, msg_len,
 	    conn->limit_kbps > 0 ? sftpio : NULL, &conn->bwlimit_in)
 	    != msg_len) {
 		if (errno == EPIPE)
@@ -151,46 +157,56 @@ get_msg(struct sftp_conn *conn, Buffer *m)
 }
 
 static void
-send_string_request(struct sftp_conn *conn, u_int id, u_int code, char *s,
+send_string_request(struct sftp_conn *conn, u_int id, u_int code, const char *s,
     u_int len)
 {
-	Buffer msg;
-
-	buffer_init(&msg);
-	buffer_put_char(&msg, code);
-	buffer_put_int(&msg, id);
-	buffer_put_string(&msg, s, len);
-	send_msg(conn, &msg);
+	struct sshbuf *msg;
+	int r;
+
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_u8(msg, code)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_string(msg, s, len)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
 	debug3("Sent message fd %d T:%u I:%u", conn->fd_out, code, id);
-	buffer_free(&msg);
+	sshbuf_free(msg);
 }
 
 static void
 send_string_attrs_request(struct sftp_conn *conn, u_int id, u_int code,
-    char *s, u_int len, Attrib *a)
+    const void *s, u_int len, Attrib *a)
 {
-	Buffer msg;
-
-	buffer_init(&msg);
-	buffer_put_char(&msg, code);
-	buffer_put_int(&msg, id);
-	buffer_put_string(&msg, s, len);
-	encode_attrib(&msg, a);
-	send_msg(conn, &msg);
+	struct sshbuf *msg;
+	int r;
+
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_u8(msg, code)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_string(msg, s, len)) != 0 ||
+	    (r = encode_attrib(msg, a)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
 	debug3("Sent message fd %d T:%u I:%u", conn->fd_out, code, id);
-	buffer_free(&msg);
+	sshbuf_free(msg);
 }
 
 static u_int
 get_status(struct sftp_conn *conn, u_int expected_id)
 {
-	Buffer msg;
-	u_int type, id, status;
+	struct sshbuf *msg;
+	u_char type;
+	u_int id, status;
+	int r;
 
-	buffer_init(&msg);
-	get_msg(conn, &msg);
-	type = buffer_get_char(&msg);
-	id = buffer_get_int(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	get_msg(conn, msg);
+	if ((r = sshbuf_get_u8(msg, &type)) != 0 ||
+	    (r = sshbuf_get_u32(msg, &id)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	if (id != expected_id)
 		fatal("ID mismatch (%u != %u)", id, expected_id);
@@ -198,112 +214,136 @@ get_status(struct sftp_conn *conn, u_int expected_id)
 		fatal("Expected SSH2_FXP_STATUS(%u) packet, got %u",
 		    SSH2_FXP_STATUS, type);
 
-	status = buffer_get_int(&msg);
-	buffer_free(&msg);
+	if ((r = sshbuf_get_u32(msg, &status)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	sshbuf_free(msg);
 
 	debug3("SSH2_FXP_STATUS %u", status);
 
 	return status;
 }
 
-static char *
-get_handle(struct sftp_conn *conn, u_int expected_id, u_int *len,
+static u_char *
+get_handle(struct sftp_conn *conn, u_int expected_id, size_t *len,
     const char *errfmt, ...)
 {
-	Buffer msg;
-	u_int type, id;
-	char *handle, errmsg[256];
+	struct sshbuf *msg;
+	u_int id, status;
+	u_char type;
+	u_char *handle;
+	char errmsg[256];
 	va_list args;
-	int status;
+	int r;
 
 	va_start(args, errfmt);
 	if (errfmt != NULL)
 		vsnprintf(errmsg, sizeof(errmsg), errfmt, args);
 	va_end(args);
 
-	buffer_init(&msg);
-	get_msg(conn, &msg);
-	type = buffer_get_char(&msg);
-	id = buffer_get_int(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	get_msg(conn, msg);
+	if ((r = sshbuf_get_u8(msg, &type)) != 0 ||
+	    (r = sshbuf_get_u32(msg, &id)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	if (id != expected_id)
 		fatal("%s: ID mismatch (%u != %u)",
 		    errfmt == NULL ? __func__ : errmsg, id, expected_id);
 	if (type == SSH2_FXP_STATUS) {
-		status = buffer_get_int(&msg);
+		if ((r = sshbuf_get_u32(msg, &status)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		if (errfmt != NULL)
 			error("%s: %s", errmsg, fx2txt(status));
-		buffer_free(&msg);
+		sshbuf_free(msg);
 		return(NULL);
 	} else if (type != SSH2_FXP_HANDLE)
 		fatal("%s: Expected SSH2_FXP_HANDLE(%u) packet, got %u",
 		    errfmt == NULL ? __func__ : errmsg, SSH2_FXP_HANDLE, type);
 
-	handle = buffer_get_string(&msg, len);
-	buffer_free(&msg);
+	if ((r = sshbuf_get_string(msg, &handle, len)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	sshbuf_free(msg);
 
-	return(handle);
+	return handle;
 }
 
 static Attrib *
 get_decode_stat(struct sftp_conn *conn, u_int expected_id, int quiet)
 {
-	Buffer msg;
-	u_int type, id;
-	Attrib *a;
+	struct sshbuf *msg;
+	u_int id;
+	u_char type;
+	int r;
+	static Attrib a;
 
-	buffer_init(&msg);
-	get_msg(conn, &msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	get_msg(conn, msg);
 
-	type = buffer_get_char(&msg);
-	id = buffer_get_int(&msg);
+	if ((r = sshbuf_get_u8(msg, &type)) != 0 ||
+	    (r = sshbuf_get_u32(msg, &id)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	debug3("Received stat reply T:%u I:%u", type, id);
 	if (id != expected_id)
 		fatal("ID mismatch (%u != %u)", id, expected_id);
 	if (type == SSH2_FXP_STATUS) {
-		int status = buffer_get_int(&msg);
+		u_int status;
 
+		if ((r = sshbuf_get_u32(msg, &status)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		if (quiet)
 			debug("Couldn't stat remote file: %s", fx2txt(status));
 		else
 			error("Couldn't stat remote file: %s", fx2txt(status));
-		buffer_free(&msg);
+		sshbuf_free(msg);
 		return(NULL);
 	} else if (type != SSH2_FXP_ATTRS) {
 		fatal("Expected SSH2_FXP_ATTRS(%u) packet, got %u",
 		    SSH2_FXP_ATTRS, type);
 	}
-	a = decode_attrib(&msg);
-	buffer_free(&msg);
+	if ((r = decode_attrib(msg, &a)) != 0) {
+		error("%s: couldn't decode attrib: %s", __func__, ssh_err(r));
+		sshbuf_free(msg);
+		return NULL;
+	}
+	sshbuf_free(msg);
 
-	return(a);
+	return &a;
 }
 
 static int
 get_decode_statvfs(struct sftp_conn *conn, struct sftp_statvfs *st,
     u_int expected_id, int quiet)
 {
-	Buffer msg;
-	u_int type, id, flag;
+	struct sshbuf *msg;
+	u_char type;
+	u_int id;
+	u_int64_t flag;
+	int r;
 
-	buffer_init(&msg);
-	get_msg(conn, &msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	get_msg(conn, msg);
 
-	type = buffer_get_char(&msg);
-	id = buffer_get_int(&msg);
+	if ((r = sshbuf_get_u8(msg, &type)) != 0 ||
+	    (r = sshbuf_get_u32(msg, &id)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	debug3("Received statvfs reply T:%u I:%u", type, id);
 	if (id != expected_id)
 		fatal("ID mismatch (%u != %u)", id, expected_id);
 	if (type == SSH2_FXP_STATUS) {
-		int status = buffer_get_int(&msg);
+		u_int status;
 
+		if ((r = sshbuf_get_u32(msg, &status)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		if (quiet)
 			debug("Couldn't statvfs: %s", fx2txt(status));
 		else
 			error("Couldn't statvfs: %s", fx2txt(status));
-		buffer_free(&msg);
+		sshbuf_free(msg);
 		return -1;
 	} else if (type != SSH2_FXP_EXTENDED_REPLY) {
 		fatal("Expected SSH2_FXP_EXTENDED_REPLY(%u) packet, got %u",
@@ -311,22 +351,23 @@ get_decode_statvfs(struct sftp_conn *conn, struct sftp_statvfs *st,
 	}
 
 	memset(st, 0, sizeof(*st));
-	st->f_bsize = buffer_get_int64(&msg);
-	st->f_frsize = buffer_get_int64(&msg);
-	st->f_blocks = buffer_get_int64(&msg);
-	st->f_bfree = buffer_get_int64(&msg);
-	st->f_bavail = buffer_get_int64(&msg);
-	st->f_files = buffer_get_int64(&msg);
-	st->f_ffree = buffer_get_int64(&msg);
-	st->f_favail = buffer_get_int64(&msg);
-	st->f_fsid = buffer_get_int64(&msg);
-	flag = buffer_get_int64(&msg);
-	st->f_namemax = buffer_get_int64(&msg);
+	if ((r = sshbuf_get_u64(msg, &st->f_bsize)) != 0 ||
+	    (r = sshbuf_get_u64(msg, &st->f_frsize)) != 0 ||
+	    (r = sshbuf_get_u64(msg, &st->f_blocks)) != 0 ||
+	    (r = sshbuf_get_u64(msg, &st->f_bfree)) != 0 ||
+	    (r = sshbuf_get_u64(msg, &st->f_bavail)) != 0 ||
+	    (r = sshbuf_get_u64(msg, &st->f_files)) != 0 ||
+	    (r = sshbuf_get_u64(msg, &st->f_ffree)) != 0 ||
+	    (r = sshbuf_get_u64(msg, &st->f_favail)) != 0 ||
+	    (r = sshbuf_get_u64(msg, &st->f_fsid)) != 0 ||
+	    (r = sshbuf_get_u64(msg, &flag)) != 0 ||
+	    (r = sshbuf_get_u64(msg, &st->f_namemax)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	st->f_flag = (flag & SSH2_FXE_STATVFS_ST_RDONLY) ? ST_RDONLY : 0;
 	st->f_flag |= (flag & SSH2_FXE_STATVFS_ST_NOSUID) ? ST_NOSUID : 0;
 
-	buffer_free(&msg);
+	sshbuf_free(msg);
 
 	return 0;
 }
@@ -335,9 +376,10 @@ struct sftp_conn *
 do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests,
     u_int64_t limit_kbps)
 {
-	u_int type;
-	Buffer msg;
+	u_char type;
+	struct sshbuf *msg;
 	struct sftp_conn *ret;
+	int r;
 
 	ret = xcalloc(1, sizeof(*ret));
 	ret->msg_id = 1;
@@ -348,52 +390,61 @@ do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests,
 	ret->exts = 0;
 	ret->limit_kbps = 0;
 
-	buffer_init(&msg);
-	buffer_put_char(&msg, SSH2_FXP_INIT);
-	buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
-	send_msg(ret, &msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_INIT)) != 0 ||
+	    (r = sshbuf_put_u32(msg, SSH2_FILEXFER_VERSION)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(ret, msg);
 
-	buffer_clear(&msg);
+	sshbuf_reset(msg);
 
-	get_msg(ret, &msg);
+	get_msg(ret, msg);
 
 	/* Expecting a VERSION reply */
-	if ((type = buffer_get_char(&msg)) != SSH2_FXP_VERSION) {
+	if ((r = sshbuf_get_u8(msg, &type)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	if (type != SSH2_FXP_VERSION) {
 		error("Invalid packet back from SSH2_FXP_INIT (type %u)",
 		    type);
-		buffer_free(&msg);
+		sshbuf_free(msg);
 		return(NULL);
 	}
-	ret->version = buffer_get_int(&msg);
+	if ((r = sshbuf_get_u32(msg, &ret->version)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	debug2("Remote version: %u", ret->version);
 
 	/* Check for extensions */
-	while (buffer_len(&msg) > 0) {
-		char *name = buffer_get_string(&msg, NULL);
-		char *value = buffer_get_string(&msg, NULL);
+	while (sshbuf_len(msg) > 0) {
+		char *name;
+		u_char *value;
+		size_t vlen;
 		int known = 0;
 
+		if ((r = sshbuf_get_cstring(msg, &name, NULL)) != 0 ||
+		    (r = sshbuf_get_string(msg, &value, &vlen)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		if (strcmp(name, "posix-rename@openssh.com") == 0 &&
-		    strcmp(value, "1") == 0) {
+		    strcmp((char *)value, "1") == 0) {
 			ret->exts |= SFTP_EXT_POSIX_RENAME;
 			known = 1;
 		} else if (strcmp(name, "statvfs@openssh.com") == 0 &&
-		    strcmp(value, "2") == 0) {
+		    strcmp((char *)value, "2") == 0) {
 			ret->exts |= SFTP_EXT_STATVFS;
 			known = 1;
 		} else if (strcmp(name, "fstatvfs@openssh.com") == 0 &&
-		    strcmp(value, "2") == 0) {
+		    strcmp((char *)value, "2") == 0) {
 			ret->exts |= SFTP_EXT_FSTATVFS;
 			known = 1;
 		} else if (strcmp(name, "hardlink@openssh.com") == 0 &&
-		    strcmp(value, "1") == 0) {
+		    strcmp((char *)value, "1") == 0) {
 			ret->exts |= SFTP_EXT_HARDLINK;
 			known = 1;
- 		} else if (strcmp(name, "fsync@openssh.com") == 0 &&
- 		    strcmp(value, "1") == 0) {
- 			ret->exts |= SFTP_EXT_FSYNC;
- 			known = 1;
+		} else if (strcmp(name, "fsync@openssh.com") == 0 &&
+		    strcmp((char *)value, "1") == 0) {
+			ret->exts |= SFTP_EXT_FSYNC;
+			known = 1;
 		}
 		if (known) {
 			debug2("Server supports extension \"%s\" revision %s",
@@ -405,7 +456,7 @@ do_init(int fd_in, int fd_out, u_int transfer_buflen, u_int num_requests,
 		free(value);
 	}
 
-	buffer_free(&msg);
+	sshbuf_free(msg);
 
 	/* Some filexfer v.0 servers don't support large packets */
 	if (ret->version == 0)
@@ -429,54 +480,62 @@ sftp_proto_version(struct sftp_conn *conn)
 }
 
 int
-do_close(struct sftp_conn *conn, char *handle, u_int handle_len)
+do_close(struct sftp_conn *conn, const u_char *handle, u_int handle_len)
 {
 	u_int id, status;
-	Buffer msg;
+	struct sshbuf *msg;
+	int r;
 
-	buffer_init(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
 
 	id = conn->msg_id++;
-	buffer_put_char(&msg, SSH2_FXP_CLOSE);
-	buffer_put_int(&msg, id);
-	buffer_put_string(&msg, handle, handle_len);
-	send_msg(conn, &msg);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_CLOSE)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_string(msg, handle, handle_len)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
 	debug3("Sent message SSH2_FXP_CLOSE I:%u", id);
 
 	status = get_status(conn, id);
 	if (status != SSH2_FX_OK)
 		error("Couldn't close file: %s", fx2txt(status));
 
-	buffer_free(&msg);
+	sshbuf_free(msg);
 
-	return status;
+	return status == SSH2_FX_OK ? 0 : -1;
 }
 
 
 static int
-do_lsreaddir(struct sftp_conn *conn, char *path, int print_flag,
+do_lsreaddir(struct sftp_conn *conn, const char *path, int print_flag,
     SFTP_DIRENT ***dir)
 {
-	Buffer msg;
-	u_int count, type, id, handle_len, i, expected_id, ents = 0;
+	struct sshbuf *msg;
+	u_int count, id, i, expected_id, ents = 0;
+	size_t handle_len;
+	u_char type;
 	char *handle;
 	int status = SSH2_FX_FAILURE;
+	int r;
 
 	if (dir)
 		*dir = NULL;
 
 	id = conn->msg_id++;
 
-	buffer_init(&msg);
-	buffer_put_char(&msg, SSH2_FXP_OPENDIR);
-	buffer_put_int(&msg, id);
-	buffer_put_cstring(&msg, path);
-	send_msg(conn, &msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_OPENDIR)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, path)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
 
 	handle = get_handle(conn, id, &handle_len,
 	    "remote readdir(\"%s\")", path);
 	if (handle == NULL) {
-		buffer_free(&msg);
+		sshbuf_free(msg);
 		return -1;
 	}
 
@@ -491,18 +550,20 @@ do_lsreaddir(struct sftp_conn *conn, char *path, int print_flag,
 
 		debug3("Sending SSH2_FXP_READDIR I:%u", id);
 
-		buffer_clear(&msg);
-		buffer_put_char(&msg, SSH2_FXP_READDIR);
-		buffer_put_int(&msg, id);
-		buffer_put_string(&msg, handle, handle_len);
-		send_msg(conn, &msg);
+		sshbuf_reset(msg);
+		if ((r = sshbuf_put_u8(msg, SSH2_FXP_READDIR)) != 0 ||
+		    (r = sshbuf_put_u32(msg, id)) != 0 ||
+		    (r = sshbuf_put_string(msg, handle, handle_len)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
+		send_msg(conn, msg);
 
-		buffer_clear(&msg);
+		sshbuf_reset(msg);
 
-		get_msg(conn, &msg);
+		get_msg(conn, msg);
 
-		type = buffer_get_char(&msg);
-		id = buffer_get_int(&msg);
+		if ((r = sshbuf_get_u8(msg, &type)) != 0 ||
+		    (r = sshbuf_get_u32(msg, &id)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 		debug3("Received reply T:%u I:%u", type, id);
 
@@ -510,27 +571,43 @@ do_lsreaddir(struct sftp_conn *conn, char *path, int print_flag,
 			fatal("ID mismatch (%u != %u)", id, expected_id);
 
 		if (type == SSH2_FXP_STATUS) {
-			status = buffer_get_int(&msg);
-			debug3("Received SSH2_FXP_STATUS %d", status);
-			if (status == SSH2_FX_EOF)
+			u_int rstatus;
+
+			if ((r = sshbuf_get_u32(msg, &rstatus)) != 0)
+				fatal("%s: buffer error: %s",
+				    __func__, ssh_err(r));
+			debug3("Received SSH2_FXP_STATUS %d", rstatus);
+			if (rstatus == SSH2_FX_EOF)
 				break;
-			error("Couldn't read directory: %s", fx2txt(status));
+			error("Couldn't read directory: %s", fx2txt(rstatus));
 			goto out;
 		} else if (type != SSH2_FXP_NAME)
 			fatal("Expected SSH2_FXP_NAME(%u) packet, got %u",
 			    SSH2_FXP_NAME, type);
 
-		count = buffer_get_int(&msg);
+		if ((r = sshbuf_get_u32(msg, &count)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		if (count == 0)
 			break;
 		debug3("Received %d SSH2_FXP_NAME responses", count);
 		for (i = 0; i < count; i++) {
 			char *filename, *longname;
-			Attrib *a;
-
-			filename = buffer_get_string(&msg, NULL);
-			longname = buffer_get_string(&msg, NULL);
-			a = decode_attrib(&msg);
+			Attrib a;
+
+			if ((r = sshbuf_get_cstring(msg, &filename,
+			    NULL)) != 0 ||
+			    (r = sshbuf_get_cstring(msg, &longname,
+			    NULL)) != 0)
+				fatal("%s: buffer error: %s",
+				    __func__, ssh_err(r));
+			if ((r = decode_attrib(msg, &a)) != 0) {
+				error("%s: couldn't decode attrib: %s",
+				    __func__, ssh_err(r));
+				free(filename);
+				free(longname);
+				sshbuf_free(msg);
+				return -1;
+			}
 
 			if (print_flag)
 				printf("%s\n", longname);
@@ -548,7 +625,7 @@ do_lsreaddir(struct sftp_conn *conn, char *path, int print_flag,
 				(*dir)[ents] = xcalloc(1, sizeof(***dir));
 				(*dir)[ents]->filename = xstrdup(filename);
 				(*dir)[ents]->longname = xstrdup(longname);
-				memcpy(&(*dir)[ents]->a, a, sizeof(*a));
+				memcpy(&(*dir)[ents]->a, &a, sizeof(a));
 				(*dir)[++ents] = NULL;
 			}
 			free(filename);
@@ -558,7 +635,7 @@ do_lsreaddir(struct sftp_conn *conn, char *path, int print_flag,
 	status = 0;
 
  out:
-	buffer_free(&msg);
+	sshbuf_free(msg);
 	do_close(conn, handle, handle_len);
 	free(handle);
 
@@ -577,7 +654,7 @@ do_lsreaddir(struct sftp_conn *conn, char *path, int print_flag,
 }
 
 int
-do_readdir(struct sftp_conn *conn, char *path, SFTP_DIRENT ***dir)
+do_readdir(struct sftp_conn *conn, const char *path, SFTP_DIRENT ***dir)
 {
 	return(do_lsreaddir(conn, path, 0, dir));
 }
@@ -597,7 +674,7 @@ void free_sftp_dirents(SFTP_DIRENT **s)
 }
 
 int
-do_rm(struct sftp_conn *conn, char *path)
+do_rm(struct sftp_conn *conn, const char *path)
 {
 	u_int status, id;
 
@@ -608,11 +685,11 @@ do_rm(struct sftp_conn *conn, char *path)
 	status = get_status(conn, id);
 	if (status != SSH2_FX_OK)
 		error("Couldn't delete file: %s", fx2txt(status));
-	return(status);
+	return status == SSH2_FX_OK ? 0 : -1;
 }
 
 int
-do_mkdir(struct sftp_conn *conn, char *path, Attrib *a, int print_flag)
+do_mkdir(struct sftp_conn *conn, const char *path, Attrib *a, int print_flag)
 {
 	u_int status, id;
 
@@ -624,11 +701,11 @@ do_mkdir(struct sftp_conn *conn, char *path, Attrib *a, int print_flag)
 	if (status != SSH2_FX_OK && print_flag)
 		error("Couldn't create directory: %s", fx2txt(status));
 
-	return(status);
+	return status == SSH2_FX_OK ? 0 : -1;
 }
 
 int
-do_rmdir(struct sftp_conn *conn, char *path)
+do_rmdir(struct sftp_conn *conn, const char *path)
 {
 	u_int status, id;
 
@@ -640,11 +717,11 @@ do_rmdir(struct sftp_conn *conn, char *path)
 	if (status != SSH2_FX_OK)
 		error("Couldn't remove directory: %s", fx2txt(status));
 
-	return(status);
+	return status == SSH2_FX_OK ? 0 : -1;
 }
 
 Attrib *
-do_stat(struct sftp_conn *conn, char *path, int quiet)
+do_stat(struct sftp_conn *conn, const char *path, int quiet)
 {
 	u_int id;
 
@@ -658,7 +735,7 @@ do_stat(struct sftp_conn *conn, char *path, int quiet)
 }
 
 Attrib *
-do_lstat(struct sftp_conn *conn, char *path, int quiet)
+do_lstat(struct sftp_conn *conn, const char *path, int quiet)
 {
 	u_int id;
 
@@ -679,7 +756,8 @@ do_lstat(struct sftp_conn *conn, char *path, int quiet)
 
 #ifdef notyet
 Attrib *
-do_fstat(struct sftp_conn *conn, char *handle, u_int handle_len, int quiet)
+do_fstat(struct sftp_conn *conn, const u_char *handle, u_int handle_len,
+    int quiet)
 {
 	u_int id;
 
@@ -692,7 +770,7 @@ do_fstat(struct sftp_conn *conn, char *handle, u_int handle_len, int quiet)
 #endif
 
 int
-do_setstat(struct sftp_conn *conn, char *path, Attrib *a)
+do_setstat(struct sftp_conn *conn, const char *path, Attrib *a)
 {
 	u_int status, id;
 
@@ -705,11 +783,11 @@ do_setstat(struct sftp_conn *conn, char *path, Attrib *a)
 		error("Couldn't setstat on \"%s\": %s", path,
 		    fx2txt(status));
 
-	return(status);
+	return status == SSH2_FX_OK ? 0 : -1;
 }
 
 int
-do_fsetstat(struct sftp_conn *conn, char *handle, u_int handle_len,
+do_fsetstat(struct sftp_conn *conn, const u_char *handle, u_int handle_len,
     Attrib *a)
 {
 	u_int status, id;
@@ -722,181 +800,201 @@ do_fsetstat(struct sftp_conn *conn, char *handle, u_int handle_len,
 	if (status != SSH2_FX_OK)
 		error("Couldn't fsetstat: %s", fx2txt(status));
 
-	return(status);
+	return status == SSH2_FX_OK ? 0 : -1;
 }
 
 char *
-do_realpath(struct sftp_conn *conn, char *path)
+do_realpath(struct sftp_conn *conn, const char *path)
 {
-	Buffer msg;
-	u_int type, expected_id, count, id;
+	struct sshbuf *msg;
+	u_int expected_id, count, id;
 	char *filename, *longname;
-	Attrib *a;
+	Attrib a;
+	u_char type;
+	int r;
 
 	expected_id = id = conn->msg_id++;
 	send_string_request(conn, id, SSH2_FXP_REALPATH, path,
 	    strlen(path));
 
-	buffer_init(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
 
-	get_msg(conn, &msg);
-	type = buffer_get_char(&msg);
-	id = buffer_get_int(&msg);
+	get_msg(conn, msg);
+	if ((r = sshbuf_get_u8(msg, &type)) != 0 ||
+	    (r = sshbuf_get_u32(msg, &id)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	if (id != expected_id)
 		fatal("ID mismatch (%u != %u)", id, expected_id);
 
 	if (type == SSH2_FXP_STATUS) {
-		u_int status = buffer_get_int(&msg);
+		u_int status;
 
+		if ((r = sshbuf_get_u32(msg, &status)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		error("Couldn't canonicalize: %s", fx2txt(status));
-		buffer_free(&msg);
+		sshbuf_free(msg);
 		return NULL;
 	} else if (type != SSH2_FXP_NAME)
 		fatal("Expected SSH2_FXP_NAME(%u) packet, got %u",
 		    SSH2_FXP_NAME, type);
 
-	count = buffer_get_int(&msg);
+	if ((r = sshbuf_get_u32(msg, &count)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	if (count != 1)
 		fatal("Got multiple names (%d) from SSH_FXP_REALPATH", count);
 
-	filename = buffer_get_string(&msg, NULL);
-	longname = buffer_get_string(&msg, NULL);
-	a = decode_attrib(&msg);
+	if ((r = sshbuf_get_cstring(msg, &filename, NULL)) != 0 ||
+	    (r = sshbuf_get_cstring(msg, &longname, NULL)) != 0 ||
+	    (r = decode_attrib(msg, &a)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	debug3("SSH_FXP_REALPATH %s -> %s size %lu", path, filename,
-	    (unsigned long)a->size);
+	    (unsigned long)a.size);
 
 	free(longname);
 
-	buffer_free(&msg);
+	sshbuf_free(msg);
 
 	return(filename);
 }
 
 int
-do_rename(struct sftp_conn *conn, char *oldpath, char *newpath,
+do_rename(struct sftp_conn *conn, const char *oldpath, const char *newpath,
     int force_legacy)
 {
-	Buffer msg;
+	struct sshbuf *msg;
 	u_int status, id;
-	int use_ext = (conn->exts & SFTP_EXT_POSIX_RENAME) && !force_legacy;
+	int r, use_ext = (conn->exts & SFTP_EXT_POSIX_RENAME) && !force_legacy;
 
-	buffer_init(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
 
 	/* Send rename request */
 	id = conn->msg_id++;
 	if (use_ext) {
-		buffer_put_char(&msg, SSH2_FXP_EXTENDED);
-		buffer_put_int(&msg, id);
-		buffer_put_cstring(&msg, "posix-rename@openssh.com");
+		if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED)) != 0 ||
+		    (r = sshbuf_put_u32(msg, id)) != 0 ||
+		    (r = sshbuf_put_cstring(msg,
+		    "posix-rename@openssh.com")) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	} else {
-		buffer_put_char(&msg, SSH2_FXP_RENAME);
-		buffer_put_int(&msg, id);
+		if ((r = sshbuf_put_u8(msg, SSH2_FXP_RENAME)) != 0 ||
+		    (r = sshbuf_put_u32(msg, id)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	}
-	buffer_put_cstring(&msg, oldpath);
-	buffer_put_cstring(&msg, newpath);
-	send_msg(conn, &msg);
+	if ((r = sshbuf_put_cstring(msg, oldpath)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, newpath)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
 	debug3("Sent message %s \"%s\" -> \"%s\"",
-	    use_ext ? "posix-rename@openssh.com" : "SSH2_FXP_RENAME",
-	    oldpath, newpath);
-	buffer_free(&msg);
+	    use_ext ? "posix-rename@openssh.com" :
+	    "SSH2_FXP_RENAME", oldpath, newpath);
+	sshbuf_free(msg);
 
 	status = get_status(conn, id);
 	if (status != SSH2_FX_OK)
 		error("Couldn't rename file \"%s\" to \"%s\": %s", oldpath,
 		    newpath, fx2txt(status));
 
-	return(status);
+	return status == SSH2_FX_OK ? 0 : -1;
 }
 
 int
-do_hardlink(struct sftp_conn *conn, char *oldpath, char *newpath)
+do_hardlink(struct sftp_conn *conn, const char *oldpath, const char *newpath)
 {
-	Buffer msg;
+	struct sshbuf *msg;
 	u_int status, id;
+	int r;
 
 	if ((conn->exts & SFTP_EXT_HARDLINK) == 0) {
 		error("Server does not support hardlink@openssh.com extension");
 		return -1;
 	}
 
-	buffer_init(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
 
 	/* Send link request */
 	id = conn->msg_id++;
-	buffer_put_char(&msg, SSH2_FXP_EXTENDED);
-	buffer_put_int(&msg, id);
-	buffer_put_cstring(&msg, "hardlink@openssh.com");
-	buffer_put_cstring(&msg, oldpath);
-	buffer_put_cstring(&msg, newpath);
-	send_msg(conn, &msg);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, "hardlink@openssh.com")) != 0 ||
+	    (r = sshbuf_put_cstring(msg, oldpath)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, newpath)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
 	debug3("Sent message hardlink@openssh.com \"%s\" -> \"%s\"",
 	       oldpath, newpath);
-	buffer_free(&msg);
+	sshbuf_free(msg);
 
 	status = get_status(conn, id);
 	if (status != SSH2_FX_OK)
 		error("Couldn't link file \"%s\" to \"%s\": %s", oldpath,
 		    newpath, fx2txt(status));
 
-	return(status);
+	return status == SSH2_FX_OK ? 0 : -1;
 }
 
 int
-do_symlink(struct sftp_conn *conn, char *oldpath, char *newpath)
+do_symlink(struct sftp_conn *conn, const char *oldpath, const char *newpath)
 {
-	Buffer msg;
+	struct sshbuf *msg;
 	u_int status, id;
+	int r;
 
 	if (conn->version < 3) {
 		error("This server does not support the symlink operation");
 		return(SSH2_FX_OP_UNSUPPORTED);
 	}
 
-	buffer_init(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
 
 	/* Send symlink request */
 	id = conn->msg_id++;
-	buffer_put_char(&msg, SSH2_FXP_SYMLINK);
-	buffer_put_int(&msg, id);
-	buffer_put_cstring(&msg, oldpath);
-	buffer_put_cstring(&msg, newpath);
-	send_msg(conn, &msg);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_SYMLINK)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, oldpath)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, newpath)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
 	debug3("Sent message SSH2_FXP_SYMLINK \"%s\" -> \"%s\"", oldpath,
 	    newpath);
-	buffer_free(&msg);
+	sshbuf_free(msg);
 
 	status = get_status(conn, id);
 	if (status != SSH2_FX_OK)
 		error("Couldn't symlink file \"%s\" to \"%s\": %s", oldpath,
 		    newpath, fx2txt(status));
 
-	return(status);
+	return status == SSH2_FX_OK ? 0 : -1;
 }
 
 int
-do_fsync(struct sftp_conn *conn, char *handle, u_int handle_len)
+do_fsync(struct sftp_conn *conn, u_char *handle, u_int handle_len)
 {
-	Buffer msg;
+	struct sshbuf *msg;
 	u_int status, id;
+	int r;
 
 	/* Silently return if the extension is not supported */
 	if ((conn->exts & SFTP_EXT_FSYNC) == 0)
 		return -1;
 
-	buffer_init(&msg);
-
 	/* Send fsync request */
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
 	id = conn->msg_id++;
-
-	buffer_put_char(&msg, SSH2_FXP_EXTENDED);
-	buffer_put_int(&msg, id);
-	buffer_put_cstring(&msg, "fsync@openssh.com");
-	buffer_put_string(&msg, handle, handle_len);
-	send_msg(conn, &msg);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, "fsync@openssh.com")) != 0 ||
+	    (r = sshbuf_put_string(msg, handle, handle_len)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
 	debug3("Sent message fsync@openssh.com I:%u", id);
-	buffer_free(&msg);
+	sshbuf_free(msg);
 
 	status = get_status(conn, id);
 	if (status != SSH2_FX_OK)
@@ -907,50 +1005,58 @@ do_fsync(struct sftp_conn *conn, char *handle, u_int handle_len)
 
 #ifdef notyet
 char *
-do_readlink(struct sftp_conn *conn, char *path)
+do_readlink(struct sftp_conn *conn, const char *path)
 {
-	Buffer msg;
-	u_int type, expected_id, count, id;
+	struct sshbuf *msg;
+	u_int expected_id, count, id;
 	char *filename, *longname;
-	Attrib *a;
+	Attrib a;
+	u_char type;
+	int r;
 
 	expected_id = id = conn->msg_id++;
 	send_string_request(conn, id, SSH2_FXP_READLINK, path, strlen(path));
 
-	buffer_init(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
 
-	get_msg(conn, &msg);
-	type = buffer_get_char(&msg);
-	id = buffer_get_int(&msg);
+	get_msg(conn, msg);
+	if ((r = sshbuf_get_u8(msg, &type)) != 0 ||
+	    (r = sshbuf_get_u32(msg, &id)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	if (id != expected_id)
 		fatal("ID mismatch (%u != %u)", id, expected_id);
 
 	if (type == SSH2_FXP_STATUS) {
-		u_int status = buffer_get_int(&msg);
+		u_int status;
 
+		if ((r = sshbuf_get_u32(msg, &status)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		error("Couldn't readlink: %s", fx2txt(status));
-		buffer_free(&msg);
+		sshbuf_free(msg);
 		return(NULL);
 	} else if (type != SSH2_FXP_NAME)
 		fatal("Expected SSH2_FXP_NAME(%u) packet, got %u",
 		    SSH2_FXP_NAME, type);
 
-	count = buffer_get_int(&msg);
+	if ((r = sshbuf_get_u32(msg, &count)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	if (count != 1)
 		fatal("Got multiple names (%d) from SSH_FXP_READLINK", count);
 
-	filename = buffer_get_string(&msg, NULL);
-	longname = buffer_get_string(&msg, NULL);
-	a = decode_attrib(&msg);
+	if ((r = sshbuf_get_cstring(msg, &filename, NULL)) != 0 ||
+	    (r = sshbuf_get_cstring(msg, &longname, NULL)) != 0 ||
+	    (r = decode_attrib(msg, &a)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	debug3("SSH_FXP_READLINK %s -> %s", path, filename);
 
 	free(longname);
 
-	buffer_free(&msg);
+	sshbuf_free(msg);
 
-	return(filename);
+	return filename;
 }
 #endif
 
@@ -958,8 +1064,9 @@ int
 do_statvfs(struct sftp_conn *conn, const char *path, struct sftp_statvfs *st,
     int quiet)
 {
-	Buffer msg;
+	struct sshbuf *msg;
 	u_int id;
+	int r;
 
 	if ((conn->exts & SFTP_EXT_STATVFS) == 0) {
 		error("Server does not support statvfs@openssh.com extension");
@@ -968,24 +1075,26 @@ do_statvfs(struct sftp_conn *conn, const char *path, struct sftp_statvfs *st,
 
 	id = conn->msg_id++;
 
-	buffer_init(&msg);
-	buffer_clear(&msg);
-	buffer_put_char(&msg, SSH2_FXP_EXTENDED);
-	buffer_put_int(&msg, id);
-	buffer_put_cstring(&msg, "statvfs@openssh.com");
-	buffer_put_cstring(&msg, path);
-	send_msg(conn, &msg);
-	buffer_free(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	sshbuf_reset(msg);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, "statvfs@openssh.com")) != 0 ||
+	    (r = sshbuf_put_cstring(msg, path)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
+	sshbuf_free(msg);
 
 	return get_decode_statvfs(conn, st, id, quiet);
 }
 
 #ifdef notyet
 int
-do_fstatvfs(struct sftp_conn *conn, const char *handle, u_int handle_len,
+do_fstatvfs(struct sftp_conn *conn, const u_char *handle, u_int handle_len,
     struct sftp_statvfs *st, int quiet)
 {
-	Buffer msg;
+	struct sshbuf *msg;
 	u_int id;
 
 	if ((conn->exts & SFTP_EXT_FSTATVFS) == 0) {
@@ -995,14 +1104,16 @@ do_fstatvfs(struct sftp_conn *conn, const char *handle, u_int handle_len,
 
 	id = conn->msg_id++;
 
-	buffer_init(&msg);
-	buffer_clear(&msg);
-	buffer_put_char(&msg, SSH2_FXP_EXTENDED);
-	buffer_put_int(&msg, id);
-	buffer_put_cstring(&msg, "fstatvfs@openssh.com");
-	buffer_put_string(&msg, handle, handle_len);
-	send_msg(conn, &msg);
-	buffer_free(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	sshbuf_reset(msg);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, "fstatvfs@openssh.com")) != 0 ||
+	    (r = sshbuf_put_string(msg, handle, handle_len)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
+	sshbuf_free(msg);
 
 	return get_decode_statvfs(conn, st, id, quiet);
 }
@@ -1010,42 +1121,48 @@ do_fstatvfs(struct sftp_conn *conn, const char *handle, u_int handle_len,
 
 static void
 send_read_request(struct sftp_conn *conn, u_int id, u_int64_t offset,
-    u_int len, char *handle, u_int handle_len)
+    u_int len, const u_char *handle, u_int handle_len)
 {
-	Buffer msg;
-
-	buffer_init(&msg);
-	buffer_clear(&msg);
-	buffer_put_char(&msg, SSH2_FXP_READ);
-	buffer_put_int(&msg, id);
-	buffer_put_string(&msg, handle, handle_len);
-	buffer_put_int64(&msg, offset);
-	buffer_put_int(&msg, len);
-	send_msg(conn, &msg);
-	buffer_free(&msg);
+	struct sshbuf *msg;
+	int r;
+
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	sshbuf_reset(msg);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_READ)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_string(msg, handle, handle_len)) != 0 ||
+	    (r = sshbuf_put_u64(msg, offset)) != 0 ||
+	    (r = sshbuf_put_u32(msg, len)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
+	sshbuf_free(msg);
 }
 
 int
-do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
-    Attrib *a, int preserve_flag, int resume_flag, int fsync_flag)
+do_download(struct sftp_conn *conn, const char *remote_path,
+    const char *local_path, Attrib *a, int preserve_flag, int resume_flag,
+    int fsync_flag)
 {
 	Attrib junk;
-	Buffer msg;
-	char *handle;
-	int local_fd = -1, status = 0, write_error;
-	int read_error, write_errno, reordered = 0;
+	struct sshbuf *msg;
+	u_char *handle;
+	int local_fd = -1, write_error;
+	int read_error, write_errno, reordered = 0, r;
 	u_int64_t offset = 0, size, highwater;
-	u_int handle_len, mode, type, id, buflen, num_req, max_req;
+	u_int mode, id, buflen, num_req, max_req, status = SSH2_FX_OK;
 	off_t progress_counter;
+	size_t handle_len;
 	struct stat st;
 	struct request {
 		u_int id;
-		u_int len;
+		size_t len;
 		u_int64_t offset;
 		TAILQ_ENTRY(request) tq;
 	};
 	TAILQ_HEAD(reqhead, request) requests;
 	struct request *req;
+	u_char type;
 
 	TAILQ_INIT(&requests);
 
@@ -1070,23 +1187,26 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
 		size = 0;
 
 	buflen = conn->transfer_buflen;
-	buffer_init(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+
+	attrib_clear(&junk); /* Send empty attributes */
 
 	/* Send open request */
 	id = conn->msg_id++;
-	buffer_put_char(&msg, SSH2_FXP_OPEN);
-	buffer_put_int(&msg, id);
-	buffer_put_cstring(&msg, remote_path);
-	buffer_put_int(&msg, SSH2_FXF_READ);
-	attrib_clear(&junk); /* Send empty attributes */
-	encode_attrib(&msg, &junk);
-	send_msg(conn, &msg);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_OPEN)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, remote_path)) != 0 ||
+	    (r = sshbuf_put_u32(msg, SSH2_FXF_READ)) != 0 ||
+	    (r = encode_attrib(msg, &junk)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
 	debug3("Sent message SSH2_FXP_OPEN I:%u P:%s", id, remote_path);
 
 	handle = get_handle(conn, id, &handle_len,
 	    "remote open(\"%s\")", remote_path);
 	if (handle == NULL) {
-		buffer_free(&msg);
+		sshbuf_free(msg);
 		return(-1);
 	}
 
@@ -1113,7 +1233,7 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
 			    "local file is larger than remote", local_path);
  fail:
 			do_close(conn, handle, handle_len);
-			buffer_free(&msg);
+			sshbuf_free(msg);
 			free(handle);
 			if (local_fd != -1)
 				close(local_fd);
@@ -1131,8 +1251,8 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
 		start_progress_meter(remote_path, size, &progress_counter);
 
 	while (num_req > 0 || max_req > 0) {
-		char *data;
-		u_int len;
+		u_char *data;
+		size_t len;
 
 		/*
 		 * Simulate EOF on interrupt: stop sending new requests and
@@ -1161,10 +1281,11 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
 			    req->len, handle, handle_len);
 		}
 
-		buffer_clear(&msg);
-		get_msg(conn, &msg);
-		type = buffer_get_char(&msg);
-		id = buffer_get_int(&msg);
+		sshbuf_reset(msg);
+		get_msg(conn, msg);
+		if ((r = sshbuf_get_u8(msg, &type)) != 0 ||
+		    (r = sshbuf_get_u32(msg, &id)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		debug3("Received reply T:%u I:%u R:%d", type, id, max_req);
 
 		/* Find the request in our queue */
@@ -1177,7 +1298,9 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
 
 		switch (type) {
 		case SSH2_FXP_STATUS:
-			status = buffer_get_int(&msg);
+			if ((r = sshbuf_get_u32(msg, &status)) != 0)
+				fatal("%s: buffer error: %s",
+				    __func__, ssh_err(r));
 			if (status != SSH2_FX_EOF)
 				read_error = 1;
 			max_req = 0;
@@ -1186,13 +1309,15 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
 			num_req--;
 			break;
 		case SSH2_FXP_DATA:
-			data = buffer_get_string(&msg, &len);
+			if ((r = sshbuf_get_string(msg, &data, &len)) != 0)
+				fatal("%s: buffer error: %s",
+				    __func__, ssh_err(r));
 			debug3("Received data %llu -> %llu",
 			    (unsigned long long)req->offset,
 			    (unsigned long long)req->offset + len - 1);
 			if (len > req->len)
 				fatal("Received more data than asked for "
-				    "%u > %u", len, req->len);
+				    "%zu > %zu", len, req->len);
 			if ((lseek(local_fd, req->offset, SEEK_SET) == -1 ||
 			    atomicio(vwrite, local_fd, data, len) != len) &&
 			    !write_error) {
@@ -1269,12 +1394,13 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
 	} else if (write_error) {
 		error("Couldn't write to \"%s\": %s", local_path,
 		    strerror(write_errno));
-		status = -1;
+		status = SSH2_FX_FAILURE;
 		do_close(conn, handle, handle_len);
 	} else {
-		status = do_close(conn, handle, handle_len);
-		if (interrupted || status != SSH2_FX_OK)
-			status = -1;
+		if (do_close(conn, handle, handle_len) != 0 || interrupted)
+			status = SSH2_FX_FAILURE;
+		else
+			status = SSH2_FX_OK;
 		/* Override umask and utimes if asked */
 #ifdef HAVE_FCHMOD
 		if (preserve_flag && fchmod(local_fd, mode) == -1)
@@ -1301,16 +1427,16 @@ do_download(struct sftp_conn *conn, char *remote_path, char *local_path,
 		}
 	}
 	close(local_fd);
-	buffer_free(&msg);
+	sshbuf_free(msg);
 	free(handle);
 
 	return(status);
 }
 
 static int
-download_dir_internal(struct sftp_conn *conn, char *src, char *dst, int depth,
-    Attrib *dirattrib, int preserve_flag, int print_flag, int resume_flag,
-    int fsync_flag)
+download_dir_internal(struct sftp_conn *conn, const char *src, const char *dst,
+    int depth, Attrib *dirattrib, int preserve_flag, int print_flag,
+    int resume_flag, int fsync_flag)
 {
 	int i, ret = 0;
 	SFTP_DIRENT **dir_entries;
@@ -1400,9 +1526,9 @@ download_dir_internal(struct sftp_conn *conn, char *src, char *dst, int depth,
 }
 
 int
-download_dir(struct sftp_conn *conn, char *src, char *dst,
-    Attrib *dirattrib, int preserve_flag, int print_flag,
-    int resume_flag, int fsync_flag)
+download_dir(struct sftp_conn *conn, const char *src, const char *dst,
+    Attrib *dirattrib, int preserve_flag, int print_flag, int resume_flag,
+    int fsync_flag)
 {
 	char *src_canon;
 	int ret;
@@ -1419,15 +1545,16 @@ download_dir(struct sftp_conn *conn, char *src, char *dst,
 }
 
 int
-do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
-    int preserve_flag, int resume, int fsync_flag)
+do_upload(struct sftp_conn *conn, const char *local_path,
+    const char *remote_path, int preserve_flag, int resume, int fsync_flag)
 {
-	int local_fd;
-	int status = SSH2_FX_OK;
-	u_int handle_len, id, type;
+	int r, local_fd;
+	u_int status = SSH2_FX_OK;
+	u_int id;
+	u_char type;
 	off_t offset, progress_counter;
-	char *handle, *data;
-	Buffer msg;
+	u_char *handle, *data;
+	struct sshbuf *msg;
 	struct stat sb;
 	Attrib a, *c = NULL;
 	u_int32_t startid;
@@ -1440,6 +1567,7 @@ do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
 	};
 	TAILQ_HEAD(ackhead, outstanding_ack) acks;
 	struct outstanding_ack *ack = NULL;
+	size_t handle_len;
 
 	TAILQ_INIT(&acks);
 
@@ -1487,26 +1615,28 @@ do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
 		}
 	}
 
-	buffer_init(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
 
 	/* Send open request */
 	id = conn->msg_id++;
-	buffer_put_char(&msg, SSH2_FXP_OPEN);
-	buffer_put_int(&msg, id);
-	buffer_put_cstring(&msg, remote_path);
-	buffer_put_int(&msg, SSH2_FXF_WRITE|SSH2_FXF_CREAT|
-		      (resume ? SSH2_FXF_APPEND : SSH2_FXF_TRUNC));
-	encode_attrib(&msg, &a);
-	send_msg(conn, &msg);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_OPEN)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_cstring(msg, remote_path)) != 0 ||
+	    (r = sshbuf_put_u32(msg, SSH2_FXF_WRITE|SSH2_FXF_CREAT|
+	    (resume ? SSH2_FXF_APPEND : SSH2_FXF_TRUNC))) != 0 ||
+	    (r = encode_attrib(msg, &a)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(conn, msg);
 	debug3("Sent message SSH2_FXP_OPEN I:%u P:%s", id, remote_path);
 
-	buffer_clear(&msg);
+	sshbuf_reset(msg);
 
 	handle = get_handle(conn, id, &handle_len,
 	    "remote open(\"%s\")", remote_path);
 	if (handle == NULL) {
 		close(local_fd);
-		buffer_free(&msg);
+		sshbuf_free(msg);
 		return -1;
 	}
 
@@ -1546,13 +1676,16 @@ do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
 			ack->len = len;
 			TAILQ_INSERT_TAIL(&acks, ack, tq);
 
-			buffer_clear(&msg);
-			buffer_put_char(&msg, SSH2_FXP_WRITE);
-			buffer_put_int(&msg, ack->id);
-			buffer_put_string(&msg, handle, handle_len);
-			buffer_put_int64(&msg, offset);
-			buffer_put_string(&msg, data, len);
-			send_msg(conn, &msg);
+			sshbuf_reset(msg);
+			if ((r = sshbuf_put_u8(msg, SSH2_FXP_WRITE)) != 0 ||
+			    (r = sshbuf_put_u32(msg, ack->id)) != 0 ||
+			    (r = sshbuf_put_string(msg, handle,
+			    handle_len)) != 0 ||
+			    (r = sshbuf_put_u64(msg, offset)) != 0 ||
+			    (r = sshbuf_put_string(msg, data, len)) != 0)
+				fatal("%s: buffer error: %s",
+				    __func__, ssh_err(r));
+			send_msg(conn, msg);
 			debug3("Sent message SSH2_FXP_WRITE I:%u O:%llu S:%u",
 			    id, (unsigned long long)offset, len);
 		} else if (TAILQ_FIRST(&acks) == NULL)
@@ -1563,27 +1696,31 @@ do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
 
 		if (id == startid || len == 0 ||
 		    id - ackid >= conn->num_requests) {
-			u_int r_id;
+			u_int rid;
 
-			buffer_clear(&msg);
-			get_msg(conn, &msg);
-			type = buffer_get_char(&msg);
-			r_id = buffer_get_int(&msg);
+			sshbuf_reset(msg);
+			get_msg(conn, msg);
+			if ((r = sshbuf_get_u8(msg, &type)) != 0 ||
+			    (r = sshbuf_get_u32(msg, &rid)) != 0)
+				fatal("%s: buffer error: %s",
+				    __func__, ssh_err(r));
 
 			if (type != SSH2_FXP_STATUS)
 				fatal("Expected SSH2_FXP_STATUS(%d) packet, "
 				    "got %d", SSH2_FXP_STATUS, type);
 
-			status = buffer_get_int(&msg);
-			debug3("SSH2_FXP_STATUS %d", status);
+			if ((r = sshbuf_get_u32(msg, &status)) != 0)
+				fatal("%s: buffer error: %s",
+				    __func__, ssh_err(r));
+			debug3("SSH2_FXP_STATUS %u", status);
 
 			/* Find the request in our queue */
 			for (ack = TAILQ_FIRST(&acks);
-			    ack != NULL && ack->id != r_id;
+			    ack != NULL && ack->id != rid;
 			    ack = TAILQ_NEXT(ack, tq))
 				;
 			if (ack == NULL)
-				fatal("Can't find request for ID %u", r_id);
+				fatal("Can't find request for ID %u", rid);
 			TAILQ_REMOVE(&acks, ack, tq);
 			debug3("In write loop, ack for %u %u bytes at %lld",
 			    ack->id, ack->len, (long long)ack->offset);
@@ -1595,7 +1732,7 @@ do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
 		if (offset < 0)
 			fatal("%s: offset < 0", __func__);
 	}
-	buffer_free(&msg);
+	sshbuf_free(msg);
 
 	if (showprogress)
 		stop_progress_meter();
@@ -1604,13 +1741,13 @@ do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
 	if (status != SSH2_FX_OK) {
 		error("Couldn't write to remote file \"%s\": %s",
 		    remote_path, fx2txt(status));
-		status = -1;
+		status = SSH2_FX_FAILURE;
 	}
 
 	if (close(local_fd) == -1) {
 		error("Couldn't close local file \"%s\": %s", local_path,
 		    strerror(errno));
-		status = -1;
+		status = SSH2_FX_FAILURE;
 	}
 
 	/* Override umask and utimes if asked */
@@ -1621,17 +1758,19 @@ do_upload(struct sftp_conn *conn, char *local_path, char *remote_path,
 		(void)do_fsync(conn, handle, handle_len);
 
 	if (do_close(conn, handle, handle_len) != SSH2_FX_OK)
-		status = -1;
+		status = SSH2_FX_FAILURE;
+
 	free(handle);
 
-	return status;
+	return status == SSH2_FX_OK ? 0 : -1;
 }
 
 static int
-upload_dir_internal(struct sftp_conn *conn, char *src, char *dst, int depth,
-    int preserve_flag, int print_flag, int resume, int fsync_flag)
+upload_dir_internal(struct sftp_conn *conn, const char *src, const char *dst,
+    int depth, int preserve_flag, int print_flag, int resume, int fsync_flag)
 {
-	int ret = 0, status;
+	int ret = 0;
+	u_int status;
 	DIR *dirp;
 	struct dirent *dp;
 	char *filename, *new_src, *new_dst;
@@ -1721,8 +1860,8 @@ upload_dir_internal(struct sftp_conn *conn, char *src, char *dst, int depth,
 }
 
 int
-upload_dir(struct sftp_conn *conn, char *src, char *dst, int preserve_flag,
-    int print_flag, int resume, int fsync_flag)
+upload_dir(struct sftp_conn *conn, const char *src, const char *dst,
+    int preserve_flag, int print_flag, int resume, int fsync_flag)
 {
 	char *dst_canon;
 	int ret;
@@ -1740,7 +1879,7 @@ upload_dir(struct sftp_conn *conn, char *src, char *dst, int preserve_flag,
 }
 
 char *
-path_append(char *p1, char *p2)
+path_append(const char *p1, const char *p2)
 {
 	char *ret;
 	size_t len = strlen(p1) + strlen(p2) + 2;
diff --git a/sftp-client.h b/sftp-client.h
index 967840b9..507d763e 100644
--- a/sftp-client.h
+++ b/sftp-client.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp-client.h,v 1.25 2014/04/21 14:36:16 logan Exp $ */
+/* $OpenBSD: sftp-client.h,v 1.26 2015/01/14 13:54:13 djm Exp $ */
 
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
@@ -56,79 +56,81 @@ struct sftp_conn *do_init(int, int, u_int, u_int, u_int64_t);
 u_int sftp_proto_version(struct sftp_conn *);
 
 /* Close file referred to by 'handle' */
-int do_close(struct sftp_conn *, char *, u_int);
+int do_close(struct sftp_conn *, const u_char *, u_int);
 
 /* Read contents of 'path' to NULL-terminated array 'dir' */
-int do_readdir(struct sftp_conn *, char *, SFTP_DIRENT ***);
+int do_readdir(struct sftp_conn *, const char *, SFTP_DIRENT ***);
 
 /* Frees a NULL-terminated array of SFTP_DIRENTs (eg. from do_readdir) */
 void free_sftp_dirents(SFTP_DIRENT **);
 
 /* Delete file 'path' */
-int do_rm(struct sftp_conn *, char *);
+int do_rm(struct sftp_conn *, const char *);
 
 /* Create directory 'path' */
-int do_mkdir(struct sftp_conn *, char *, Attrib *, int);
+int do_mkdir(struct sftp_conn *, const char *, Attrib *, int);
 
 /* Remove directory 'path' */
-int do_rmdir(struct sftp_conn *, char *);
+int do_rmdir(struct sftp_conn *, const char *);
 
 /* Get file attributes of 'path' (follows symlinks) */
-Attrib *do_stat(struct sftp_conn *, char *, int);
+Attrib *do_stat(struct sftp_conn *, const char *, int);
 
 /* Get file attributes of 'path' (does not follow symlinks) */
-Attrib *do_lstat(struct sftp_conn *, char *, int);
+Attrib *do_lstat(struct sftp_conn *, const char *, int);
 
 /* Set file attributes of 'path' */
-int do_setstat(struct sftp_conn *, char *, Attrib *);
+int do_setstat(struct sftp_conn *, const char *, Attrib *);
 
 /* Set file attributes of open file 'handle' */
-int do_fsetstat(struct sftp_conn *, char *, u_int, Attrib *);
+int do_fsetstat(struct sftp_conn *, const u_char *, u_int, Attrib *);
 
 /* Canonicalise 'path' - caller must free result */
-char *do_realpath(struct sftp_conn *, char *);
+char *do_realpath(struct sftp_conn *, const char *);
 
 /* Get statistics for filesystem hosting file at "path" */
 int do_statvfs(struct sftp_conn *, const char *, struct sftp_statvfs *, int);
 
 /* Rename 'oldpath' to 'newpath' */
-int do_rename(struct sftp_conn *, char *, char *m, int force_legacy);
+int do_rename(struct sftp_conn *, const char *, const char *, int force_legacy);
 
 /* Link 'oldpath' to 'newpath' */
-int do_hardlink(struct sftp_conn *, char *, char *);
+int do_hardlink(struct sftp_conn *, const char *, const char *);
 
 /* Rename 'oldpath' to 'newpath' */
-int do_symlink(struct sftp_conn *, char *, char *);
+int do_symlink(struct sftp_conn *, const char *, const char *);
 
 /* Call fsync() on open file 'handle' */
-int do_fsync(struct sftp_conn *conn, char *, u_int);
+int do_fsync(struct sftp_conn *conn, u_char *, u_int);
 
 /*
  * Download 'remote_path' to 'local_path'. Preserve permissions and times
  * if 'pflag' is set
  */
-int do_download(struct sftp_conn *, char *, char *, Attrib *, int, int, int);
+int do_download(struct sftp_conn *, const char *, const char *,
+    Attrib *, int, int, int);
 
 /*
  * Recursively download 'remote_directory' to 'local_directory'. Preserve 
  * times if 'pflag' is set
  */
-int download_dir(struct sftp_conn *, char *, char *, Attrib *, int,
-    int, int, int);
+int download_dir(struct sftp_conn *, const char *, const char *,
+    Attrib *, int, int, int, int);
 
 /*
  * Upload 'local_path' to 'remote_path'. Preserve permissions and times
  * if 'pflag' is set
  */
-int do_upload(struct sftp_conn *, char *, char *, int, int, int);
+int do_upload(struct sftp_conn *, const char *, const char *, int, int, int);
 
 /*
  * Recursively upload 'local_directory' to 'remote_directory'. Preserve 
  * times if 'pflag' is set
  */
-int upload_dir(struct sftp_conn *, char *, char *, int, int, int, int);
+int upload_dir(struct sftp_conn *, const char *, const char *, int, int, int,
+    int);
 
 /* Concatenate paths, taking care of slashes. Caller must free result. */
-char *path_append(char *, char *);
+char *path_append(const char *, const char *);
 
 #endif
diff --git a/sftp-common.c b/sftp-common.c
index 70a929cc..9c54d5c6 100644
--- a/sftp-common.c
+++ b/sftp-common.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp-common.c,v 1.26 2014/01/09 03:26:00 guenther Exp $ */
+/* $OpenBSD: sftp-common.c,v 1.27 2015/01/14 13:54:13 djm Exp $ */
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
  * Copyright (c) 2001 Damien Miller.  All rights reserved.
@@ -42,7 +42,8 @@
 #endif
 
 #include "xmalloc.h"
-#include "buffer.h"
+#include "ssherr.h"
+#include "sshbuf.h"
 #include "log.h"
 
 #include "sftp.h"
@@ -100,59 +101,81 @@ attrib_to_stat(const Attrib *a, struct stat *st)
 }
 
 /* Decode attributes in buffer */
-Attrib *
-decode_attrib(Buffer *b)
+int
+decode_attrib(struct sshbuf *b, Attrib *a)
 {
-	static Attrib a;
-
-	attrib_clear(&a);
-	a.flags = buffer_get_int(b);
-	if (a.flags & SSH2_FILEXFER_ATTR_SIZE)
-		a.size = buffer_get_int64(b);
-	if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
-		a.uid = buffer_get_int(b);
-		a.gid = buffer_get_int(b);
-	}
-	if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS)
-		a.perm = buffer_get_int(b);
-	if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
-		a.atime = buffer_get_int(b);
-		a.mtime = buffer_get_int(b);
+	int r;
+
+	attrib_clear(a);
+	if ((r = sshbuf_get_u32(b, &a->flags)) != 0)
+		return r;
+	if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
+		if ((r = sshbuf_get_u64(b, &a->size)) != 0)
+			return r;
+	}
+	if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
+		if ((r = sshbuf_get_u32(b, &a->uid)) != 0 ||
+		    (r = sshbuf_get_u32(b, &a->gid)) != 0)
+			return r;
+	}
+	if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
+		if ((r = sshbuf_get_u32(b, &a->perm)) != 0)
+			return r;
+	}
+	if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
+		if ((r = sshbuf_get_u32(b, &a->atime)) != 0 ||
+		    (r = sshbuf_get_u32(b, &a->mtime)) != 0)
+			return r;
 	}
 	/* vendor-specific extensions */
-	if (a.flags & SSH2_FILEXFER_ATTR_EXTENDED) {
-		char *type, *data;
-		int i, count;
+	if (a->flags & SSH2_FILEXFER_ATTR_EXTENDED) {
+		char *type;
+		u_char *data;
+		size_t dlen;
+		u_int i, count;
 
-		count = buffer_get_int(b);
+		if ((r = sshbuf_get_u32(b, &count)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		for (i = 0; i < count; i++) {
-			type = buffer_get_string(b, NULL);
-			data = buffer_get_string(b, NULL);
-			debug3("Got file attribute \"%s\"", type);
+			if ((r = sshbuf_get_cstring(b, &type, NULL)) != 0 ||
+			    (r = sshbuf_get_string(b, &data, &dlen)) != 0)
+				return r;
+			debug3("Got file attribute \"%.100s\" len %zu",
+			    type, dlen);
 			free(type);
 			free(data);
 		}
 	}
-	return &a;
+	return 0;
 }
 
 /* Encode attributes to buffer */
-void
-encode_attrib(Buffer *b, const Attrib *a)
+int
+encode_attrib(struct sshbuf *b, const Attrib *a)
 {
-	buffer_put_int(b, a->flags);
-	if (a->flags & SSH2_FILEXFER_ATTR_SIZE)
-		buffer_put_int64(b, a->size);
+	int r;
+
+	if ((r = sshbuf_put_u32(b, a->flags)) != 0)
+		return r;
+	if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
+		if ((r = sshbuf_put_u64(b, a->size)) != 0)
+			return r;
+	}
 	if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
-		buffer_put_int(b, a->uid);
-		buffer_put_int(b, a->gid);
+		if ((r = sshbuf_put_u32(b, a->uid)) != 0 ||
+		    (r = sshbuf_put_u32(b, a->gid)) != 0)
+			return r;
+	}
+	if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
+		if ((r = sshbuf_put_u32(b, a->perm)) != 0)
+			return r;
 	}
-	if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS)
-		buffer_put_int(b, a->perm);
 	if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
-		buffer_put_int(b, a->atime);
-		buffer_put_int(b, a->mtime);
+		if ((r = sshbuf_put_u32(b, a->atime)) != 0 ||
+		    (r = sshbuf_put_u32(b, a->mtime)) != 0)
+			return r;
 	}
+	return 0;
 }
 
 /* Convert from SSH2_FX_ status to text error message */
diff --git a/sftp-common.h b/sftp-common.h
index 9ed86c07..2e778a9c 100644
--- a/sftp-common.h
+++ b/sftp-common.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp-common.h,v 1.11 2010/01/13 01:40:16 djm Exp $ */
+/* $OpenBSD: sftp-common.h,v 1.12 2015/01/14 13:54:13 djm Exp $ */
 
 /*
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -28,6 +28,7 @@
 /* Maximum packet that we are willing to send/accept */
 #define SFTP_MAX_MSG_LENGTH	(256 * 1024)
 
+struct sshbuf;
 typedef struct Attrib Attrib;
 
 /* File attributes */
@@ -44,8 +45,8 @@ struct Attrib {
 void	 attrib_clear(Attrib *);
 void	 stat_to_attrib(const struct stat *, Attrib *);
 void	 attrib_to_stat(const Attrib *, struct stat *);
-Attrib	*decode_attrib(Buffer *);
-void	 encode_attrib(Buffer *, const Attrib *);
+int	 decode_attrib(struct sshbuf *, Attrib *);
+int	 encode_attrib(struct sshbuf *, const Attrib *);
 char	*ls_file(const char *, const struct stat *, int, int);
 
 const char *fx2txt(int);
diff --git a/sftp-glob.c b/sftp-glob.c
index d85aecc9..43a1beba 100644
--- a/sftp-glob.c
+++ b/sftp-glob.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp-glob.c,v 1.26 2013/11/08 11:15:19 dtucker Exp $ */
+/* $OpenBSD: sftp-glob.c,v 1.27 2015/01/14 13:54:13 djm Exp $ */
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
  *
@@ -25,10 +25,10 @@
 #include <dirent.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdlib.h>
 
 #include "xmalloc.h"
 #include "sftp.h"
-#include "buffer.h"
 #include "sftp-common.h"
 #include "sftp-client.h"
 
diff --git a/sftp-server.c b/sftp-server.c
index 0177130c..aeff1aa1 100644
--- a/sftp-server.c
+++ b/sftp-server.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp-server.c,v 1.103 2014/01/17 06:23:24 dtucker Exp $ */
+/* $OpenBSD: sftp-server.c,v 1.104 2015/01/14 13:54:13 djm Exp $ */
 /*
  * Copyright (c) 2000-2004 Markus Friedl.  All rights reserved.
  *
@@ -46,7 +46,8 @@
 #include <stdarg.h>
 
 #include "xmalloc.h"
-#include "buffer.h"
+#include "sshbuf.h"
+#include "ssherr.h"
 #include "log.h"
 #include "misc.h"
 #include "match.h"
@@ -55,11 +56,6 @@
 #include "sftp.h"
 #include "sftp-common.h"
 
-/* helper */
-#define get_int64()			buffer_get_int64(&iqueue);
-#define get_int()			buffer_get_int(&iqueue);
-#define get_string(lenp)		buffer_get_string(&iqueue, lenp);
-
 /* Our verbosity */
 static LogLevel log_level = SYSLOG_LEVEL_ERROR;
 
@@ -68,8 +64,8 @@ static struct passwd *pw = NULL;
 static char *client_addr = NULL;
 
 /* input and output queue */
-static Buffer iqueue;
-static Buffer oqueue;
+struct sshbuf *iqueue;
+struct sshbuf *oqueue;
 
 /* Version of client */
 static u_int version;
@@ -275,12 +271,6 @@ string_from_portable(int pflags)
 	return ret;
 }
 
-static Attrib *
-get_attrib(void)
-{
-	return decode_attrib(&iqueue);
-}
-
 /* handle handles */
 
 typedef struct Handle Handle;
@@ -344,7 +334,7 @@ handle_is_ok(int i, int type)
 }
 
 static int
-handle_to_string(int handle, char **stringp, int *hlenp)
+handle_to_string(int handle, u_char **stringp, int *hlenp)
 {
 	if (stringp == NULL || hlenp == NULL)
 		return -1;
@@ -355,7 +345,7 @@ handle_to_string(int handle, char **stringp, int *hlenp)
 }
 
 static int
-handle_from_string(const char *handle, u_int hlen)
+handle_from_string(const u_char *handle, u_int hlen)
 {
 	int val;
 
@@ -477,29 +467,31 @@ handle_log_exit(void)
 }
 
 static int
-get_handle(void)
+get_handle(struct sshbuf *queue, int *hp)
 {
-	char *handle;
-	int val = -1;
-	u_int hlen;
+	u_char *handle;
+	int r;
+	size_t hlen;
 
-	handle = get_string(&hlen);
+	*hp = -1;
+	if ((r = sshbuf_get_string(queue, &handle, &hlen)) != 0)
+		return r;
 	if (hlen < 256)
-		val = handle_from_string(handle, hlen);
+		*hp = handle_from_string(handle, hlen);
 	free(handle);
-	return val;
+	return 0;
 }
 
 /* send replies */
 
 static void
-send_msg(Buffer *m)
+send_msg(struct sshbuf *m)
 {
-	int mlen = buffer_len(m);
+	int r;
 
-	buffer_put_int(&oqueue, mlen);
-	buffer_append(&oqueue, buffer_ptr(m), mlen);
-	buffer_consume(m, mlen);
+	if ((r = sshbuf_put_stringb(oqueue, m)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	sshbuf_reset(m);
 }
 
 static const char *
@@ -523,38 +515,46 @@ status_to_message(u_int32_t status)
 static void
 send_status(u_int32_t id, u_int32_t status)
 {
-	Buffer msg;
+	struct sshbuf *msg;
+	int r;
 
 	debug3("request %u: sent status %u", id, status);
 	if (log_level > SYSLOG_LEVEL_VERBOSE ||
 	    (status != SSH2_FX_OK && status != SSH2_FX_EOF))
 		logit("sent status %s", status_to_message(status));
-	buffer_init(&msg);
-	buffer_put_char(&msg, SSH2_FXP_STATUS);
-	buffer_put_int(&msg, id);
-	buffer_put_int(&msg, status);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_STATUS)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_u32(msg, status)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	if (version >= 3) {
-		buffer_put_cstring(&msg, status_to_message(status));
-		buffer_put_cstring(&msg, "");
+		if ((r = sshbuf_put_cstring(msg,
+		    status_to_message(status))) != 0 ||
+		    (r = sshbuf_put_cstring(msg, "")) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	}
-	send_msg(&msg);
-	buffer_free(&msg);
+	send_msg(msg);
+	sshbuf_free(msg);
 }
 static void
-send_data_or_handle(char type, u_int32_t id, const char *data, int dlen)
+send_data_or_handle(char type, u_int32_t id, const u_char *data, int dlen)
 {
-	Buffer msg;
-
-	buffer_init(&msg);
-	buffer_put_char(&msg, type);
-	buffer_put_int(&msg, id);
-	buffer_put_string(&msg, data, dlen);
-	send_msg(&msg);
-	buffer_free(&msg);
+	struct sshbuf *msg;
+	int r;
+
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_u8(msg, type)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_string(msg, data, dlen)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(msg);
+	sshbuf_free(msg);
 }
 
 static void
-send_data(u_int32_t id, const char *data, int dlen)
+send_data(u_int32_t id, const u_char *data, int dlen)
 {
 	debug("request %u: sent data len %d", id, dlen);
 	send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
@@ -563,7 +563,7 @@ send_data(u_int32_t id, const char *data, int dlen)
 static void
 send_handle(u_int32_t id, int handle)
 {
-	char *string;
+	u_char *string;
 	int hlen;
 
 	handle_to_string(handle, &string, &hlen);
@@ -575,62 +575,71 @@ send_handle(u_int32_t id, int handle)
 static void
 send_names(u_int32_t id, int count, const Stat *stats)
 {
-	Buffer msg;
-	int i;
-
-	buffer_init(&msg);
-	buffer_put_char(&msg, SSH2_FXP_NAME);
-	buffer_put_int(&msg, id);
-	buffer_put_int(&msg, count);
+	struct sshbuf *msg;
+	int i, r;
+
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_NAME)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_u32(msg, count)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	debug("request %u: sent names count %d", id, count);
 	for (i = 0; i < count; i++) {
-		buffer_put_cstring(&msg, stats[i].name);
-		buffer_put_cstring(&msg, stats[i].long_name);
-		encode_attrib(&msg, &stats[i].attrib);
+		if ((r = sshbuf_put_cstring(msg, stats[i].name)) != 0 ||
+		    (r = sshbuf_put_cstring(msg, stats[i].long_name)) != 0 ||
+		    (r = encode_attrib(msg, &stats[i].attrib)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	}
-	send_msg(&msg);
-	buffer_free(&msg);
+	send_msg(msg);
+	sshbuf_free(msg);
 }
 
 static void
 send_attrib(u_int32_t id, const Attrib *a)
 {
-	Buffer msg;
+	struct sshbuf *msg;
+	int r;
 
 	debug("request %u: sent attrib have 0x%x", id, a->flags);
-	buffer_init(&msg);
-	buffer_put_char(&msg, SSH2_FXP_ATTRS);
-	buffer_put_int(&msg, id);
-	encode_attrib(&msg, a);
-	send_msg(&msg);
-	buffer_free(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_ATTRS)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = encode_attrib(msg, a)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(msg);
+	sshbuf_free(msg);
 }
 
 static void
 send_statvfs(u_int32_t id, struct statvfs *st)
 {
-	Buffer msg;
+	struct sshbuf *msg;
 	u_int64_t flag;
+	int r;
 
 	flag = (st->f_flag & ST_RDONLY) ? SSH2_FXE_STATVFS_ST_RDONLY : 0;
 	flag |= (st->f_flag & ST_NOSUID) ? SSH2_FXE_STATVFS_ST_NOSUID : 0;
 
-	buffer_init(&msg);
-	buffer_put_char(&msg, SSH2_FXP_EXTENDED_REPLY);
-	buffer_put_int(&msg, id);
-	buffer_put_int64(&msg, st->f_bsize);
-	buffer_put_int64(&msg, st->f_frsize);
-	buffer_put_int64(&msg, st->f_blocks);
-	buffer_put_int64(&msg, st->f_bfree);
-	buffer_put_int64(&msg, st->f_bavail);
-	buffer_put_int64(&msg, st->f_files);
-	buffer_put_int64(&msg, st->f_ffree);
-	buffer_put_int64(&msg, st->f_favail);
-	buffer_put_int64(&msg, FSID_TO_ULONG(st->f_fsid));
-	buffer_put_int64(&msg, flag);
-	buffer_put_int64(&msg, st->f_namemax);
-	send_msg(&msg);
-	buffer_free(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_EXTENDED_REPLY)) != 0 ||
+	    (r = sshbuf_put_u32(msg, id)) != 0 ||
+	    (r = sshbuf_put_u64(msg, st->f_bsize)) != 0 ||
+	    (r = sshbuf_put_u64(msg, st->f_frsize)) != 0 ||
+	    (r = sshbuf_put_u64(msg, st->f_blocks)) != 0 ||
+	    (r = sshbuf_put_u64(msg, st->f_bfree)) != 0 ||
+	    (r = sshbuf_put_u64(msg, st->f_bavail)) != 0 ||
+	    (r = sshbuf_put_u64(msg, st->f_files)) != 0 ||
+	    (r = sshbuf_put_u64(msg, st->f_ffree)) != 0 ||
+	    (r = sshbuf_put_u64(msg, st->f_favail)) != 0 ||
+	    (r = sshbuf_put_u64(msg, FSID_TO_ULONG(st->f_fsid))) != 0 ||
+	    (r = sshbuf_put_u64(msg, flag)) != 0 ||
+	    (r = sshbuf_put_u64(msg, st->f_namemax)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(msg);
+	sshbuf_free(msg);
 }
 
 /* parse incoming */
@@ -638,53 +647,59 @@ send_statvfs(u_int32_t id, struct statvfs *st)
 static void
 process_init(void)
 {
-	Buffer msg;
+	struct sshbuf *msg;
+	int r;
 
-	version = get_int();
+	if ((r = sshbuf_get_u32(iqueue, &version)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	verbose("received client version %u", version);
-	buffer_init(&msg);
-	buffer_put_char(&msg, SSH2_FXP_VERSION);
-	buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
-	/* POSIX rename extension */
-	buffer_put_cstring(&msg, "posix-rename@openssh.com");
-	buffer_put_cstring(&msg, "1"); /* version */
-	/* statvfs extension */
-	buffer_put_cstring(&msg, "statvfs@openssh.com");
-	buffer_put_cstring(&msg, "2"); /* version */
-	/* fstatvfs extension */
-	buffer_put_cstring(&msg, "fstatvfs@openssh.com");
-	buffer_put_cstring(&msg, "2"); /* version */
-	/* hardlink extension */
-	buffer_put_cstring(&msg, "hardlink@openssh.com");
-	buffer_put_cstring(&msg, "1"); /* version */
-	/* fsync extension */
-	buffer_put_cstring(&msg, "fsync@openssh.com");
-	buffer_put_cstring(&msg, "1"); /* version */
-	send_msg(&msg);
-	buffer_free(&msg);
+	if ((msg = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_u8(msg, SSH2_FXP_VERSION)) != 0 ||
+	    (r = sshbuf_put_u32(msg, SSH2_FILEXFER_VERSION)) != 0 ||
+	    /* POSIX rename extension */
+	    (r = sshbuf_put_cstring(msg, "posix-rename@openssh.com")) != 0 ||
+	    (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */
+	    /* statvfs extension */
+	    (r = sshbuf_put_cstring(msg, "statvfs@openssh.com")) != 0 ||
+	    (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */
+	    /* fstatvfs extension */
+	    (r = sshbuf_put_cstring(msg, "fstatvfs@openssh.com")) != 0 ||
+	    (r = sshbuf_put_cstring(msg, "2")) != 0 || /* version */
+	    /* hardlink extension */
+	    (r = sshbuf_put_cstring(msg, "hardlink@openssh.com")) != 0 ||
+	    (r = sshbuf_put_cstring(msg, "1")) != 0 || /* version */
+	    /* fsync extension */
+	    (r = sshbuf_put_cstring(msg, "fsync@openssh.com")) != 0 ||
+	    (r = sshbuf_put_cstring(msg, "1")) != 0) /* version */
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	send_msg(msg);
+	sshbuf_free(msg);
 }
 
 static void
 process_open(u_int32_t id)
 {
 	u_int32_t pflags;
-	Attrib *a;
+	Attrib a;
 	char *name;
-	int handle, fd, flags, mode, status = SSH2_FX_FAILURE;
+	int r, handle, fd, flags, mode, status = SSH2_FX_FAILURE;
+
+	if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
+	    (r = sshbuf_get_u32(iqueue, &pflags)) != 0 || /* portable flags */
+	    (r = decode_attrib(iqueue, &a)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	name = get_string(NULL);
-	pflags = get_int();		/* portable flags */
 	debug3("request %u: open flags %d", id, pflags);
-	a = get_attrib();
 	flags = flags_from_portable(pflags);
-	mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a->perm : 0666;
+	mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a.perm : 0666;
 	logit("open \"%s\" flags %s mode 0%o",
 	    name, string_from_portable(pflags), mode);
 	if (readonly &&
 	    ((flags & O_ACCMODE) == O_WRONLY ||
 	    (flags & O_ACCMODE) == O_RDWR)) {
 		verbose("Refusing open request in read-only mode");
-	  	status = SSH2_FX_PERMISSION_DENIED;
+		status = SSH2_FX_PERMISSION_DENIED;
 	} else {
 		fd = open(name, flags, mode);
 		if (fd < 0) {
@@ -707,9 +722,11 @@ process_open(u_int32_t id)
 static void
 process_close(u_int32_t id)
 {
-	int handle, ret, status = SSH2_FX_FAILURE;
+	int r, handle, ret, status = SSH2_FX_FAILURE;
+
+	if ((r = get_handle(iqueue, &handle)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	handle = get_handle();
 	debug3("request %u: close handle %u", id, handle);
 	handle_log_close(handle, NULL);
 	ret = handle_close(handle);
@@ -720,14 +737,15 @@ process_close(u_int32_t id)
 static void
 process_read(u_int32_t id)
 {
-	char buf[64*1024];
+	u_char buf[64*1024];
 	u_int32_t len;
-	int handle, fd, ret, status = SSH2_FX_FAILURE;
+	int r, handle, fd, ret, status = SSH2_FX_FAILURE;
 	u_int64_t off;
 
-	handle = get_handle();
-	off = get_int64();
-	len = get_int();
+	if ((r = get_handle(iqueue, &handle)) != 0 ||
+	    (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
+	    (r = sshbuf_get_u32(iqueue, &len)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	debug("request %u: read \"%s\" (handle %d) off %llu len %d",
 	    id, handle_to_name(handle), handle, (unsigned long long)off, len);
@@ -761,18 +779,19 @@ static void
 process_write(u_int32_t id)
 {
 	u_int64_t off;
-	u_int len;
-	int handle, fd, ret, status;
-	char *data;
+	size_t len;
+	int r, handle, fd, ret, status;
+	u_char *data;
 
-	handle = get_handle();
-	off = get_int64();
-	data = get_string(&len);
+	if ((r = get_handle(iqueue, &handle)) != 0 ||
+	    (r = sshbuf_get_u64(iqueue, &off)) != 0 ||
+	    (r = sshbuf_get_string(iqueue, &data, &len)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	debug("request %u: write \"%s\" (handle %d) off %llu len %d",
+	debug("request %u: write \"%s\" (handle %d) off %llu len %zu",
 	    id, handle_to_name(handle), handle, (unsigned long long)off, len);
 	fd = handle_to_fd(handle);
-	
+
 	if (fd < 0)
 		status = SSH2_FX_FAILURE;
 	else {
@@ -805,13 +824,15 @@ process_do_stat(u_int32_t id, int do_lstat)
 	Attrib a;
 	struct stat st;
 	char *name;
-	int ret, status = SSH2_FX_FAILURE;
+	int r, status = SSH2_FX_FAILURE;
+
+	if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	name = get_string(NULL);
 	debug3("request %u: %sstat", id, do_lstat ? "l" : "");
 	verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
-	ret = do_lstat ? lstat(name, &st) : stat(name, &st);
-	if (ret < 0) {
+	r = do_lstat ? lstat(name, &st) : stat(name, &st);
+	if (r < 0) {
 		status = errno_to_portable(errno);
 	} else {
 		stat_to_attrib(&st, &a);
@@ -840,15 +861,16 @@ process_fstat(u_int32_t id)
 {
 	Attrib a;
 	struct stat st;
-	int fd, ret, handle, status = SSH2_FX_FAILURE;
+	int fd, r, handle, status = SSH2_FX_FAILURE;
 
-	handle = get_handle();
+	if ((r = get_handle(iqueue, &handle)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	debug("request %u: fstat \"%s\" (handle %u)",
 	    id, handle_to_name(handle), handle);
 	fd = handle_to_fd(handle);
 	if (fd >= 0) {
-		ret = fstat(fd, &st);
-		if (ret < 0) {
+		r = fstat(fd, &st);
+		if (r < 0) {
 			status = errno_to_portable(errno);
 		} else {
 			stat_to_attrib(&st, &a);
@@ -875,42 +897,44 @@ attrib_to_tv(const Attrib *a)
 static void
 process_setstat(u_int32_t id)
 {
-	Attrib *a;
+	Attrib a;
 	char *name;
-	int status = SSH2_FX_OK, ret;
+	int r, status = SSH2_FX_OK;
+
+	if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
+	    (r = decode_attrib(iqueue, &a)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	name = get_string(NULL);
-	a = get_attrib();
 	debug("request %u: setstat name \"%s\"", id, name);
-	if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
+	if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
 		logit("set \"%s\" size %llu",
-		    name, (unsigned long long)a->size);
-		ret = truncate(name, a->size);
-		if (ret == -1)
+		    name, (unsigned long long)a.size);
+		r = truncate(name, a.size);
+		if (r == -1)
 			status = errno_to_portable(errno);
 	}
-	if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
-		logit("set \"%s\" mode %04o", name, a->perm);
-		ret = chmod(name, a->perm & 07777);
-		if (ret == -1)
+	if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
+		logit("set \"%s\" mode %04o", name, a.perm);
+		r = chmod(name, a.perm & 07777);
+		if (r == -1)
 			status = errno_to_portable(errno);
 	}
-	if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
+	if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
 		char buf[64];
-		time_t t = a->mtime;
+		time_t t = a.mtime;
 
 		strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
 		    localtime(&t));
 		logit("set \"%s\" modtime %s", name, buf);
-		ret = utimes(name, attrib_to_tv(a));
-		if (ret == -1)
+		r = utimes(name, attrib_to_tv(&a));
+		if (r == -1)
 			status = errno_to_portable(errno);
 	}
-	if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
+	if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
 		logit("set \"%s\" owner %lu group %lu", name,
-		    (u_long)a->uid, (u_long)a->gid);
-		ret = chown(name, a->uid, a->gid);
-		if (ret == -1)
+		    (u_long)a.uid, (u_long)a.gid);
+		r = chown(name, a.uid, a.gid);
+		if (r == -1)
 			status = errno_to_portable(errno);
 	}
 	send_status(id, status);
@@ -920,12 +944,78 @@ process_setstat(u_int32_t id)
 static void
 process_fsetstat(u_int32_t id)
 {
-	Attrib *a;
-	int handle, fd, ret;
+	Attrib a;
+	int handle, fd, r;
+	int status = SSH2_FX_OK;
+
+	if ((r = get_handle(iqueue, &handle)) != 0 ||
+	    (r = decode_attrib(iqueue, &a)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+	debug("request %u: fsetstat handle %d", id, handle);
+	fd = handle_to_fd(handle);
+	if (fd < 0)
+		status = SSH2_FX_FAILURE;
+	else {
+		char *name = handle_to_name(handle);
+
+		if (a.flags & SSH2_FILEXFER_ATTR_SIZE) {
+			logit("set \"%s\" size %llu",
+			    name, (unsigned long long)a.size);
+			r = ftruncate(fd, a.size);
+			if (r == -1)
+				status = errno_to_portable(errno);
+		}
+		if (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
+			logit("set \"%s\" mode %04o", name, a.perm);
+#ifdef HAVE_FCHMOD
+			ret = fchmod(fd, a->perm & 07777);
+#else
+			ret = chmod(name, a->perm & 07777);
+#endif
+			if (r == -1)
+				status = errno_to_portable(errno);
+		}
+		if (a.flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
+			char buf[64];
+			time_t t = a.mtime;
+
+			strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
+			    localtime(&t));
+			logit("set \"%s\" modtime %s", name, buf);
+#ifdef HAVE_FUTIMES
+			ret = futimes(fd, attrib_to_tv(a));
+#else
+			ret = utimes(name, attrib_to_tv(a));
+#endif
+			if (r == -1)
+				status = errno_to_portable(errno);
+		}
+		if (a.flags & SSH2_FILEXFER_ATTR_UIDGID) {
+			logit("set \"%s\" owner %lu group %lu", name,
+			    (u_long)a.uid, (u_long)a.gid);
+#ifdef HAVE_FCHOWN
+			ret = fchown(fd, a->uid, a->gid);
+#else
+			ret = chown(name, a->uid, a->gid);
+#endif
+			if (r == -1)
+				status = errno_to_portable(errno);
+		}
+	}
+	send_status(id, status);
+}
+static void
+process_fsetstat(u_int32_t id)
+{
+	Attrib a;
+	int handle, fd, r;
 	int status = SSH2_FX_OK;
 
-	handle = get_handle();
-	a = get_attrib();
+	if ((r = get_handle(iqueue, &handle)) != 0 ||
+	    (r = decode_attrib(iqueue, &a)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
 	debug("request %u: fsetstat handle %d", id, handle);
 	fd = handle_to_fd(handle);
 	if (fd < 0)
@@ -985,9 +1075,11 @@ process_opendir(u_int32_t id)
 {
 	DIR *dirp = NULL;
 	char *path;
-	int handle, status = SSH2_FX_FAILURE;
+	int r, handle, status = SSH2_FX_FAILURE;
+
+	if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	path = get_string(NULL);
 	debug3("request %u: opendir", id);
 	logit("opendir \"%s\"", path);
 	dirp = opendir(path);
@@ -1014,9 +1106,11 @@ process_readdir(u_int32_t id)
 	DIR *dirp;
 	struct dirent *dp;
 	char *path;
-	int handle;
+	int r, handle;
+
+	if ((r = get_handle(iqueue, &handle)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	handle = get_handle();
 	debug("request %u: readdir \"%s\" (handle %d)", id,
 	    handle_to_name(handle), handle);
 	dirp = handle_to_dir(handle);
@@ -1066,14 +1160,15 @@ static void
 process_remove(u_int32_t id)
 {
 	char *name;
-	int status = SSH2_FX_FAILURE;
-	int ret;
+	int r, status = SSH2_FX_FAILURE;
+
+	if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	name = get_string(NULL);
 	debug3("request %u: remove", id);
 	logit("remove name \"%s\"", name);
-	ret = unlink(name);
-	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	r = unlink(name);
+	status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 	send_status(id, status);
 	free(name);
 }
@@ -1081,18 +1176,20 @@ process_remove(u_int32_t id)
 static void
 process_mkdir(u_int32_t id)
 {
-	Attrib *a;
+	Attrib a;
 	char *name;
-	int ret, mode, status = SSH2_FX_FAILURE;
+	int r, mode, status = SSH2_FX_FAILURE;
+
+	if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0 ||
+	    (r = decode_attrib(iqueue, &a)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	name = get_string(NULL);
-	a = get_attrib();
-	mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
-	    a->perm & 07777 : 0777;
+	mode = (a.flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
+	    a.perm & 07777 : 0777;
 	debug3("request %u: mkdir", id);
 	logit("mkdir name \"%s\" mode 0%o", name, mode);
-	ret = mkdir(name, mode);
-	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	r = mkdir(name, mode);
+	status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 	send_status(id, status);
 	free(name);
 }
@@ -1101,13 +1198,15 @@ static void
 process_rmdir(u_int32_t id)
 {
 	char *name;
-	int ret, status;
+	int r, status;
+
+	if ((r = sshbuf_get_cstring(iqueue, &name, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	name = get_string(NULL);
 	debug3("request %u: rmdir", id);
 	logit("rmdir name \"%s\"", name);
-	ret = rmdir(name);
-	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	r = rmdir(name);
+	status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 	send_status(id, status);
 	free(name);
 }
@@ -1117,8 +1216,11 @@ process_realpath(u_int32_t id)
 {
 	char resolvedname[MAXPATHLEN];
 	char *path;
+	int r;
+
+	if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	path = get_string(NULL);
 	if (path[0] == '\0') {
 		free(path);
 		path = xstrdup(".");
@@ -1140,11 +1242,13 @@ static void
 process_rename(u_int32_t id)
 {
 	char *oldpath, *newpath;
-	int status;
+	int r, status;
 	struct stat sb;
 
-	oldpath = get_string(NULL);
-	newpath = get_string(NULL);
+	if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
+	    (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
 	debug3("request %u: rename", id);
 	logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
 	status = SSH2_FX_FAILURE;
@@ -1197,11 +1301,13 @@ process_rename(u_int32_t id)
 static void
 process_readlink(u_int32_t id)
 {
-	int len;
+	int r, len;
 	char buf[MAXPATHLEN];
 	char *path;
 
-	path = get_string(NULL);
+	if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
 	debug3("request %u: readlink", id);
 	verbose("readlink \"%s\"", path);
 	if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
@@ -1221,15 +1327,17 @@ static void
 process_symlink(u_int32_t id)
 {
 	char *oldpath, *newpath;
-	int ret, status;
+	int r, status;
+
+	if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
+	    (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	oldpath = get_string(NULL);
-	newpath = get_string(NULL);
 	debug3("request %u: symlink", id);
 	logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
 	/* this will fail if 'newpath' exists */
-	ret = symlink(oldpath, newpath);
-	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	r = symlink(oldpath, newpath);
+	status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 	send_status(id, status);
 	free(oldpath);
 	free(newpath);
@@ -1239,14 +1347,16 @@ static void
 process_extended_posix_rename(u_int32_t id)
 {
 	char *oldpath, *newpath;
-	int ret, status;
+	int r, status;
+
+	if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
+	    (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	oldpath = get_string(NULL);
-	newpath = get_string(NULL);
 	debug3("request %u: posix-rename", id);
 	logit("posix-rename old \"%s\" new \"%s\"", oldpath, newpath);
-	ret = rename(oldpath, newpath);
-	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	r = rename(oldpath, newpath);
+	status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 	send_status(id, status);
 	free(oldpath);
 	free(newpath);
@@ -1257,8 +1367,10 @@ process_extended_statvfs(u_int32_t id)
 {
 	char *path;
 	struct statvfs st;
+	int r;
 
-	path = get_string(NULL);
+	if ((r = sshbuf_get_cstring(iqueue, &path, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	debug3("request %u: statvfs", id);
 	logit("statvfs \"%s\"", path);
 
@@ -1272,10 +1384,11 @@ process_extended_statvfs(u_int32_t id)
 static void
 process_extended_fstatvfs(u_int32_t id)
 {
-	int handle, fd;
+	int r, handle, fd;
 	struct statvfs st;
 
-	handle = get_handle();
+	if ((r = get_handle(iqueue, &handle)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	debug("request %u: fstatvfs \"%s\" (handle %u)",
 	    id, handle_to_name(handle), handle);
 	if ((fd = handle_to_fd(handle)) < 0) {
@@ -1292,14 +1405,16 @@ static void
 process_extended_hardlink(u_int32_t id)
 {
 	char *oldpath, *newpath;
-	int ret, status;
+	int r, status;
+
+	if ((r = sshbuf_get_cstring(iqueue, &oldpath, NULL)) != 0 ||
+	    (r = sshbuf_get_cstring(iqueue, &newpath, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
-	oldpath = get_string(NULL);
-	newpath = get_string(NULL);
 	debug3("request %u: hardlink", id);
 	logit("hardlink old \"%s\" new \"%s\"", oldpath, newpath);
-	ret = link(oldpath, newpath);
-	status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+	r = link(oldpath, newpath);
+	status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 	send_status(id, status);
 	free(oldpath);
 	free(newpath);
@@ -1308,16 +1423,17 @@ process_extended_hardlink(u_int32_t id)
 static void
 process_extended_fsync(u_int32_t id)
 {
-	int handle, fd, ret, status = SSH2_FX_OP_UNSUPPORTED;
+	int handle, fd, r, status = SSH2_FX_OP_UNSUPPORTED;
 
-	handle = get_handle();
+	if ((r = get_handle(iqueue, &handle)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	debug3("request %u: fsync (handle %u)", id, handle);
 	verbose("fsync \"%s\"", handle_to_name(handle));
 	if ((fd = handle_to_fd(handle)) < 0)
 		status = SSH2_FX_NO_SUCH_FILE;
 	else if (handle_is_ok(handle, HANDLE_FILE)) {
-		ret = fsync(fd);
-		status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
+		r = fsync(fd);
+		status = (r == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 	}
 	send_status(id, status);
 }
@@ -1326,9 +1442,10 @@ static void
 process_extended(u_int32_t id)
 {
 	char *request;
-	u_int i;
+	int i, r;
 
-	request = get_string(NULL);
+	if ((r = sshbuf_get_cstring(iqueue, &request, NULL)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	for (i = 0; extended_handlers[i].handler != NULL; i++) {
 		if (strcmp(request, extended_handlers[i].ext_name) == 0) {
 			if (!request_permitted(&extended_handlers[i]))
@@ -1350,14 +1467,18 @@ process_extended(u_int32_t id)
 static void
 process(void)
 {
-	u_int msg_len, buf_len, consumed, type, i;
-	u_char *cp;
+	u_int msg_len;
+	u_int buf_len;
+	u_int consumed;
+	u_char type;
+	const u_char *cp;
+	int i, r;
 	u_int32_t id;
 
-	buf_len = buffer_len(&iqueue);
+	buf_len = sshbuf_len(iqueue);
 	if (buf_len < 5)
 		return;		/* Incomplete message. */
-	cp = buffer_ptr(&iqueue);
+	cp = sshbuf_ptr(iqueue);
 	msg_len = get_u32(cp);
 	if (msg_len > SFTP_MAX_MSG_LENGTH) {
 		error("bad message from %s local user %s",
@@ -1366,9 +1487,11 @@ process(void)
 	}
 	if (buf_len < msg_len + 4)
 		return;
-	buffer_consume(&iqueue, 4);
+	if ((r = sshbuf_consume(iqueue, 4)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 	buf_len -= 4;
-	type = buffer_get_char(&iqueue);
+	if ((r = sshbuf_get_u8(iqueue, &type)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 
 	switch (type) {
 	case SSH2_FXP_INIT:
@@ -1378,13 +1501,15 @@ process(void)
 	case SSH2_FXP_EXTENDED:
 		if (!init_done)
 			fatal("Received extended request before init");
-		id = get_int();
+		if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		process_extended(id);
 		break;
 	default:
 		if (!init_done)
 			fatal("Received %u request before init", type);
-		id = get_int();
+		if ((r = sshbuf_get_u32(iqueue, &id)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
 		for (i = 0; handlers[i].handler != NULL; i++) {
 			if (type == handlers[i].type) {
 				if (!request_permitted(&handlers[i])) {
@@ -1400,17 +1525,18 @@ process(void)
 			error("Unknown message %u", type);
 	}
 	/* discard the remaining bytes from the current packet */
-	if (buf_len < buffer_len(&iqueue)) {
+	if (buf_len < sshbuf_len(iqueue)) {
 		error("iqueue grew unexpectedly");
 		sftp_server_cleanup_exit(255);
 	}
-	consumed = buf_len - buffer_len(&iqueue);
+	consumed = buf_len - sshbuf_len(iqueue);
 	if (msg_len < consumed) {
 		error("msg_len %u < consumed %u", msg_len, consumed);
 		sftp_server_cleanup_exit(255);
 	}
-	if (msg_len > consumed)
-		buffer_consume(&iqueue, msg_len - consumed);
+	if (msg_len > consumed &&
+	    (r = sshbuf_consume(iqueue, msg_len - consumed)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
 }
 
 /* Cleanup handler that logs active handles upon normal exit */
@@ -1443,7 +1569,7 @@ int
 sftp_server_main(int argc, char **argv, struct passwd *user_pw)
 {
 	fd_set *rset, *wset;
-	int i, in, out, max, ch, skipargs = 0, log_stderr = 0;
+	int i, r, in, out, max, ch, skipargs = 0, log_stderr = 0;
 	ssize_t len, olen, set_size;
 	SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
 	char *cp, *homedir = NULL, buf[4*4096];
@@ -1565,8 +1691,10 @@ sftp_server_main(int argc, char **argv, struct passwd *user_pw)
 	if (out > max)
 		max = out;
 
-	buffer_init(&iqueue);
-	buffer_init(&oqueue);
+	if ((iqueue = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((oqueue = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
 
 	set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
 	rset = (fd_set *)xmalloc(set_size);
@@ -1588,11 +1716,15 @@ sftp_server_main(int argc, char **argv, struct passwd *user_pw)
 		 * the worst-case length packet it can generate,
 		 * otherwise apply backpressure by stopping reads.
 		 */
-		if (buffer_check_alloc(&iqueue, sizeof(buf)) &&
-		    buffer_check_alloc(&oqueue, SFTP_MAX_MSG_LENGTH))
+		if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 &&
+		    (r = sshbuf_check_reserve(oqueue,
+		    SFTP_MAX_MSG_LENGTH)) == 0)
 			FD_SET(in, rset);
+		else if (r != SSH_ERR_NO_BUFFER_SPACE)
+			fatal("%s: sshbuf_check_reserve failed: %s",
+			    __func__, ssh_err(r));
 
-		olen = buffer_len(&oqueue);
+		olen = sshbuf_len(oqueue);
 		if (olen > 0)
 			FD_SET(out, wset);
 
@@ -1612,18 +1744,20 @@ sftp_server_main(int argc, char **argv, struct passwd *user_pw)
 			} else if (len < 0) {
 				error("read: %s", strerror(errno));
 				sftp_server_cleanup_exit(1);
-			} else {
-				buffer_append(&iqueue, buf, len);
+			} else if ((r = sshbuf_put(iqueue, buf, len)) != 0) {
+				fatal("%s: buffer error: %s",
+				    __func__, ssh_err(r));
 			}
 		}
 		/* send oqueue to stdout */
 		if (FD_ISSET(out, wset)) {
-			len = write(out, buffer_ptr(&oqueue), olen);
+			len = write(out, sshbuf_ptr(oqueue), olen);
 			if (len < 0) {
 				error("write: %s", strerror(errno));
 				sftp_server_cleanup_exit(1);
-			} else {
-				buffer_consume(&oqueue, len);
+			} else if ((r = sshbuf_consume(oqueue, len)) != 0) {
+				fatal("%s: buffer error: %s",
+				    __func__, ssh_err(r));
 			}
 		}
 
@@ -1632,7 +1766,11 @@ sftp_server_main(int argc, char **argv, struct passwd *user_pw)
 		 * into the output buffer, otherwise stop processing input
 		 * and let the output queue drain.
 		 */
-		if (buffer_check_alloc(&oqueue, SFTP_MAX_MSG_LENGTH))
+		r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH);
+		if (r == 0)
 			process();
+		else if (r != SSH_ERR_NO_BUFFER_SPACE)
+			fatal("%s: sshbuf_check_reserve: %s",
+			    __func__, ssh_err(r));
 	}
 }
diff --git a/sftp.c b/sftp.c
index 98a146ed..eee472d0 100644
--- a/sftp.c
+++ b/sftp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp.c,v 1.168 2014/11/26 18:34:51 millert Exp $ */
+/* $OpenBSD: sftp.c,v 1.169 2015/01/14 13:54:13 djm Exp $ */
 /*
  * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
  *
@@ -63,7 +63,8 @@ typedef void EditLine;
 #include "misc.h"
 
 #include "sftp.h"
-#include "buffer.h"
+#include "ssherr.h"
+#include "sshbuf.h"
 #include "sftp-common.h"
 #include "sftp-client.h"